Faculty Publications: February, 2018

Query Results from the Smithsonian/NASA Astrophysics Data System (ADS)

 go to Most Recent Faculty Publications

 

Title:
Mechanics and statistics of the worm-like chain
Authors:
Marantan, Andrew; Mahadevan, L.
Publication:
American Journal of Physics, Volume 86, Issue 2, p.86-94
Publication Date:
02/2018
Origin:
AIP
Abstract Copyright:
2018: American Association of Physics Teachers
DOI:
10.1119/1.5003376
Bibliographic Code:
2018AmJPh..86...86M

Abstract

The worm-like chain model is a simple continuum model for the statistical mechanics of a flexible polymer subject to an external force. We offer a tutorial introduction to it using three approaches. First, we use a mesoscopic view, treating a long polymer (in two dimensions) as though it were made of many groups of correlated links or "clinks," allowing us to calculate its average extension as a function of the external force via scaling arguments. We then provide a standard statistical mechanics approach, obtaining the average extension by two different means: the equipartition theorem and the partition function. Finally, we work in a probabilistic framework, taking advantage of the Gaussian properties of the chain in the large-force limit to improve upon the previous calculations of the average extension.

 

Title:
A Model of Titan-like Chemistry to Connect Experiments and Cassini Observations
Authors:
Raymond, Alexander W.; Sciamma-O’Brien, Ella; Salama, Farid; Mazur, Eric
Publication:
The Astrophysical Journal, Volume 853, Issue 2, article id. 107, 17 pp. (2018). (ApJ Homepage)
Publication Date:
02/2018
Origin:
IOP
Astronomy Keywords:
astrochemistry, methods: laboratory: molecular, molecular processes, planets and satellites: atmospheres, planets and satellites: individual: Titan, plasmas
DOI:
10.3847/1538-4357/aaa12c
Bibliographic Code:
2018ApJ...853..107R

Abstract

A numerical model is presented for interpreting the chemical pathways that lead to the experimental mass spectra acquired in the Titan Haze Simulation (THS) laboratory experiments and for comparing the electron density and temperature of the THS plasma to observations made at Titan by the Cassini spacecraft. The THS plasma is a pulsed glow-discharge experiment designed to simulate the reaction of N2/CH4-dominated gas in Titan's upper atmosphere. The transient, one-dimensional model of THS chemistry tracks the evolution of more than 120 species in the direction of the plasma flow. As the minor species C2H2 and C2H4 are added to the N2/CH4-based mixture, the model correctly predicts the emergence of reaction products with up to five carbon atoms in relative abundances that agree well with measured mass spectra. Chemical growth in Titan's upper atmosphere transpires through ion–neutral and neutral–neutral chemistry, and the main reactions involving a series of known atmospheric species are retrieved from the calculation. The model indicates that the electron density and chemistry are steady during more than 99% of the 300 μs long discharge pulse. The model also suggests that the THS ionization fraction and electron temperature are comparable to those measured in Titan's upper atmosphere. These findings reaffirm that the THS plasma is a controlled analog environment for studying the first and intermediate steps of chemistry in Titan's upper atmosphere.

 

Title:
A Color-locus Method for Mapping R V Using Ensembles of Stars
Authors:
Lee, Albert; Green, Gregory M.; Schlafly, Edward F.; Finkbeiner, Douglas P.; Burgett, William; Chambers, Ken; Flewelling, Heather; Hodapp, Klaus; Kaiser, Nick; Kudritzki, Rolf-Peter; Magnier, Eugene; Metcalfe, Nigel; Wainscoat, Richard; Waters, Christopher
Publication:
The Astrophysical Journal, Volume 854, Issue 2, article id. 79, 20 pp. (2018). (ApJ Homepage)
Publication Date:
02/2018
Origin:
IOP
Astronomy Keywords:
dust, extinction, Galaxy: structure, ISM: clouds, ISM: general, local interstellar matter, stars: statistics
DOI:
10.3847/1538-4357/aaaa6d
Bibliographic Code:
2018ApJ...854...79L

Abstract

We present a simple but effective technique for measuring angular variation in R V across the sky. We divide stars from the Pan-STARRS1 catalog into Healpix pixels and determine the posterior distribution of reddening and R V for each pixel using two independent Monte Carlo methods. We find the two methods to be self-consistent in the limits where they are expected to perform similarly. We also find some agreement with high-precision photometric studies of R V in Perseus and Ophiuchus, as well as with a map of reddening near the Galactic plane based on stellar spectra from APOGEE. While current studies of R V are mostly limited to isolated clouds, we have developed a systematic method for comparing R V values for the majority of observable dust. This is a proof of concept for a more rigorous Galactic reddening map.

 

Title:
Probing the Small-scale Structure in Strongly Lensed Systems via Transdimensional Inference
Authors:
Daylan, Tansu; Cyr-Racine, Francis-Yan; Diaz Rivero, Ana; Dvorkin, Cora; Finkbeiner, Douglas P.
Publication:
The Astrophysical Journal, Volume 854, Issue 2, article id. 141, 22 pp. (2018). (ApJ Homepage)
Publication Date:
02/2018
Origin:
IOP
Astronomy Keywords:
dark matter, gravitational lensing: strong, methods: data analysis
DOI:
10.3847/1538-4357/aaaa1e
Bibliographic Code:
2018ApJ...854..141D

Abstract

Strong lensing is a sensitive probe of the small-scale density fluctuations in the Universe. We implement a pipeline to model strongly lensed systems using probabilistic cataloging, which is a transdimensional, hierarchical, and Bayesian framework to sample from a metamodel (union of models with different dimensionality) consistent with observed photon count maps. Probabilistic cataloging allows one to robustly characterize modeling covariances within and across lens models with different numbers of subhalos. Unlike traditional cataloging of subhalos, it does not require model subhalos to improve the goodness of fit above the detection threshold. Instead, it allows the exploitation of all information contained in the photon count maps—for instance, when constraining the subhalo mass function. We further show that, by not including these small subhalos in the lens model, fixed-dimensional inference methods can significantly mismodel the data. Using a simulated Hubble Space Telescope data set, we show that the subhalo mass function can be probed even when many subhalos in the sample catalogs are individually below the detection threshold and would be absent in a traditional catalog. The implemented software, Probabilistic Cataloger (PCAT) is made publicly available at https://github.com/tdaylan/pcat.

 

Title:
The DECam Plane Survey: Optical Photometry of Two Billion Objects in the Southern Galactic Plane
Authors:
Schlafly, E. F.; Green, G. M.; Lang, D.; Daylan, T.; Finkbeiner, D. P.; Lee, A.; Meisner, A. M.; Schlegel, D.; Valdes, F.
Publication:
The Astrophysical Journal Supplement Series, Volume 234, Issue 2, article id. 39, 19 pp. (2018). (ApJS Homepage)
Publication Date:
02/2018
Origin:
IOP
Astronomy Keywords:
catalogs, surveys, techniques: photometric
DOI:
10.3847/1538-4365/aaa3e2
Bibliographic Code:
2018ApJS..234...39S

Abstract

The DECam Plane Survey is a five-band optical and near-infrared survey of the southern Galactic plane with the Dark Energy Camera at Cerro Tololo. The survey is designed to reach past the main-sequence turn-off of old populations at the distance of the Galactic center through a reddening E(B-V) of 1.5 mag. Typical single-exposure depths are 23.7, 22.8, 22.3, 21.9, and 21.0 mag (AB) in the grizY bands, with seeing around 1\prime\prime . The footprint covers the Galactic plane with | b| ≲ 4^\circ , 5^\circ > l> -120^\circ . The survey pipeline simultaneously solves for the positions and fluxes of tens of thousands of sources in each image, delivering positions and fluxes of roughly two billion stars with better than 10 mmag precision. Most of these objects are highly reddened and deep in the Galactic disk, probing the structure and properties of the Milky Way and its interstellar medium. The fully-processed images and derived catalogs are publicly available.

 

Title:
Higgscitement: Cosmological Dynamics of Fine Tuning
Authors:
Amin, Mustafa A.; Fan, JiJi; Lozanov, Kaloian D.; Reece, Matthew
Publication:
eprint arXiv:1802.00444
Publication Date:
02/2018
Origin:
ARXIV
Keywords:
High Energy Physics - Phenomenology, Astrophysics - Cosmology and Nongalactic Astrophysics
Comment:
6 pages + 13 page supplementary material, 10 figures
Bibliographic Code:
2018arXiv180200444A

Abstract

The Higgs potential appears to be fine-tuned, hence very sensitive to values of other scalar fields that couple to the Higgs. We show that this feature can lead to a new epoch in the early universe featuring violent dynamics coupling the Higgs to a scalar modulus. The oscillating modulus drives tachyonic Higgs particle production. We find a simple parametric understanding of when this process can lead to rapid modulus fragmentation, resulting in gravitational wave production. A nontrivial equation-of-state arising from the nonlinear dynamics also affects the time elapsed from inflation to the CMB, influencing fits of inflationary models. Supersymmetric theories automatically contain useful ingredients for this picture.

 

Title:
D-type Conformal Matter and SU/USp Quivers
Authors:
Kim, Hee-Cheol; Razamat, Shlomo S.; Vafa, Cumrun; Zafrir, Gabi
Publication:
eprint arXiv:1802.00620
Publication Date:
02/2018
Origin:
ARXIV
Keywords:
High Energy Physics - Theory
Comment:
38 pages, 13 figures
Bibliographic Code:
2018arXiv180200620K

Abstract

We discuss the four dimensional models obtained by compactifying a single M5 brane probing $D_{N}$ singularity (minimal D-type $(1,0)$ conformal matter in six dimensions) on a torus with flux for abelian subgroups of the $SO(4N)$ flavor symmetry. We derive the resulting quiver field theories in four dimensions by first compactifying on a circle and relating the flux to duality domain walls in five dimensions. This leads to novel ${\cal N}=1$ dualities in 4 dimensions which arise from distinct five dimensional realizations of the circle compactifications of the D-type conformal matter.

 

Title:
Building Symmetry Enriched Topological Phases from a Bipartite Lattice Construction and Anyon Condensation
Authors:
Lee, Jong Yeon; Turner, Ari; Vishwanath, Ashvin
Publication:
eprint arXiv:1802.02155
Publication Date:
02/2018
Origin:
ARXIV
Keywords:
Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Mesoscale and Nanoscale Physics
Comment:
29 pages; 5 figures & 5 tables
Bibliographic Code:
2018arXiv180202155L

Abstract

We introduce a construction of symmetry-enriched topological orders on bipartite lattices in which two $\mathbb{Z}_2$ spin liquids defined on each sublattice are combined, and then anyons are condensed to reduce the topological order. By choosing different anyon condensate structures, one can vary the fractionalization pattern of the resulting spin liquid, some of which cannot be readily constructed from parton based approaches. We demonstrate the construction for $i$) a spin-1/2 honeycomb lattice where we construct a featureless state as well as intermediate states with topological order, $ii$) a nonsymmorphic lattice, and $iii$) lattices with magnetic translation symmetry. At last, we discuss constraints on non-chiral topological orders in a bosonic system under magnetic field.

 

Title:
Erratum for Ricci-flat graphs with girth at least five
Authors:
Cushing, David; Kangaslampi, Riikka; Lin, Yong; Liu, Shiping; Lu, Linyuan; Yau, Shing-Tung
Publication:
eprint arXiv:1802.02979
Publication Date:
02/2018
Origin:
ARXIV
Keywords:
Mathematics - Combinatorics, 05C99
Bibliographic Code:
2018arXiv180202979C

Abstract

This erratum will correct the classification of Theorem 1 in Lin-Lu-Yau, Comm. Anal. Geom., 2014, that misses the Triplex graph.

 

Title:
Ricci-flat cubic graphs with girth five
Authors:
Cushing, David; Kangaslampi, Riikka; Lin, Yong; Liu, Shiping; Lu, Linyuan; Yau, Shing-Tung
Publication:
eprint arXiv:1802.02982
Publication Date:
02/2018
Origin:
ARXIV
Keywords:
Mathematics - Combinatorics, 05C99
Bibliographic Code:
2018arXiv180202982C

Abstract

We classify all connected, simple, 3-regular graphs with girth at least 5 that are Ricci-flat. We use the definition of Ricci curvature on graphs given in Lin-Lu-Yau, Tohoku Math., 2011, which is a variation of Ollivier, J. Funct. Anal., 2009. A graph is Ricci-flat, if it has vanishing Ricci curvature on all edges. We show, that the only Ricci-flat cubic graphs with girth at least 5 are the Petersen graph, the Triplex and the dodecahedral graph. This will correct the classification in Lin-Lu-Yau, Comm. Anal. Geom., 2014, that misses the Triplex.

 

Title:
Evolution of the quantum Hall bulk spectrum into chiral edge states
Authors:
Patlatiuk, Taras; Scheller, Christian P.; Hill, Daniel; Tserkovnyak, Yaroslav; Barak, Gilad; Yacoby, Amir; Pfeiffer, Loren N.; West, Ken W.; Zumbühl, Dominik M.
Publication:
eprint arXiv:1802.03847
Publication Date:
02/2018
Origin:
ARXIV
Keywords:
Condensed Matter - Mesoscale and Nanoscale Physics
Comment:
8 pages, 4 color figures, including supplementary on arXiv
Bibliographic Code:
2018arXiv180203847P

Abstract

One of the most intriguing and fundamental properties of topological materials is the correspondence between the conducting edge states and the gapped bulk spectrum. So far, it has been impossible to access the full evolution of edge states with critical parameters such as magnetic field due to poor resolution, remnant bulk conductivity, or disorder. Here, we use a GaAs cleaved edge quantum wire to perform momentum-resolved tunneling spectroscopy. This allows us to probe the evolution of the chiral quantum Hall edge states and their positions from the sample edge with unprecedented precision from very low magnetic fields all the way to high fields where depopulation occurs. We present consistent analytical and numerical models, inferring the edge states from the well known bulk spectrum, finding excellent agreement with the experiment -- thus providing direct evidence for the bulk to edge correspondence. In addition, we observe various features beyond the single-particle picture, such as Fermi level pinning, exchange-enhanced spin splitting and signatures of edge-state reconstruction.

 

Title:
Variational principle for quantum impurity systems in and out of equilibrium: application to Kondo problems
Authors:
Ashida, Yuto; Shi, Tao; Bañuls, Mari Carmen; Cirac, J. Ignacio; Demler, Eugene
Publication:
eprint arXiv:1802.03861
Publication Date:
02/2018
Origin:
ARXIV
Keywords:
Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Quantum Gases, Condensed Matter - Statistical Mechanics, Quantum Physics
Comment:
15 pages, 9 figures
Bibliographic Code:
2018arXiv180203861A

Abstract

We provide a detailed formulation of the recently proposed variational approach [arXiv:1801.05825] to study ground-state properties and out-of-equilibrium dynamics for generic quantum spin-impurity systems. Motivated by the original ideas by Tomonaga, Lee, Low, and Pines, we construct a canonical transformation that completely decouples the impurity from the bath degrees of freedom. By combining this transformation with a Gaussian ansatz for the fermionic bath, we obtain a family of variational many-body states that can efficiently encode the strong entanglement between the impurity and fermions of the bath. We give a detailed derivation of equations of motions in the imaginary- and real-time evolutions on the variational manifold. We benchmark our approach by applying it to investigate ground-state and dynamical properties of the anisotropic Kondo model and compare results with those obtained using matrix-product state (MPS) ansatz. We show that our approach can achieve an accuracy comparable to MPS-based methods with several orders of magnitude fewer variational parameters than the corresponding MPS ansatz. We use our approach to investigate the two-lead Kondo model and analyze its long-time spatiotemporal behavior and the influence of a magnetic field on the conductance. The obtained results are consistent with the previous findings in the Anderson model and the exact solutions at the Toulouse point.

 

Title:
Topological Defect Lines and Renormalization Group Flows in Two Dimensions
Authors:
Chang, Chi-Ming; Lin, Ying-Hsuan; Shao, Shu-Heng; Wang, Yifan; Yin, Xi
Publication:
eprint arXiv:1802.04445
Publication Date:
02/2018
Origin:
ARXIV
Keywords:
High Energy Physics - Theory, Condensed Matter - Strongly Correlated Electrons
Comment:
98 pages, 61 figures, 2 tables; v2: minor changes, added references
Bibliographic Code:
2018arXiv180204445C

Abstract

We consider topological defect lines (TDLs) in two-dimensional conformal field theories. Generalizing and encompassing both global symmetries and Verlinde lines, TDLs together with their attached defect operators provide models of fusion categories without braiding. We study the crossing relations of TDLs, discuss their relation to the 't Hooft anomaly, and use them to constrain renormalization group flows to either conformal critical points or topological quantum field theories (TQFTs). We show that if certain non-invertible TDLs are preserved along a RG flow, then the vacuum cannot be a non-degenerate gapped state. For various massive flows, we determine the infrared TQFTs completely from the consideration of TDLs together with modular invariance.

 

Title:
Magnetic-field Induced Pair Density Wave State in the Cuprate Vortex Halo
Authors:
Edkins, Stephen D.; Kostin, Andrey; Fujita, Kazuhiro; Mackenzie, Andrew P.; Eisaki, Hiroshi; Uchida, Shin-Ichi; Sachdev, Subir; Lawler, Michael J.; Kim, Eun-Ah; Séamus Davis, J. C.; Hamidian, Mohammad H.
Publication:
eprint arXiv:1802.04673
Publication Date:
02/2018
Origin:
ARXIV
Keywords:
Condensed Matter - Superconductivity
Bibliographic Code:
2018arXiv180204673E

Abstract

When very high magnetic fields suppress the superconductivity in underdoped cuprates, an exceptional new electronic phase appears. It supports remarkable and unexplained quantum oscillations and exhibits an unidentified density wave (DW) state. Although generally referred to as a "charge" density wave (CDW) because of the observed charge density modulations, theory indicates that this could actually be the far more elusive electron-pair density wave state (PDW). To search for evidence of a field-induced PDW in cuprates, we visualize the modulations in the density of electronic states $N(\bf{r})$ within the halo surrounding Bi$_2$Sr$_2$CaCu$_2$O$_8$ vortex cores. This reveals multiple signatures of a field-induced PDW, including two sets of $N(\bf{r})$ modulations occurring at wavevectors $\bf{Q}_P$ and $2\bf{Q}_P$, both having predominantly $s$-symmetry form factors, the amplitude of the latter decaying twice as rapidly as the former, along with induced energy-gap modulations at $\bf{Q}_P$ . Such a microscopic phenomenology is in detailed agreement with theory for a field-induced primary PDW that generates secondary CDWs within the vortex halo. These data indicate that the fundamental state generated by increasing magnetic fields from the underdoped cuprate superconducting phase is actually a PDW with approximately eight CuO$_2$ unit-cell periodicity ($\lambda = 8a_0$) and predominantly $d$-symmetry form factor.

 

Title:
Measuring the self-assembly kinetics of individual viral capsids
Authors:
Garmann, Rees F.; Goldfain, Aaron M.; Manoharan, Vinothan N.
Publication:
eprint arXiv:1802.05211
Publication Date:
02/2018
Origin:
ARXIV
Keywords:
Condensed Matter - Soft Condensed Matter, Physics - Biological Physics
Comment:
58 pages, 18 figures
Bibliographic Code:
2018arXiv180205211G

Abstract

Self-assembly is widely used by biological systems to build complex and functional nanoscale structures, but the assembly pathways are difficult to observe because of the small length scales and wide range of time scales involved. We describe a label-free optical method to directly probe the assembly of individual nanostructures, and we apply it to measure the kinetics of assembly of viral capsids 28 nm in diameter and consisting of 90 protein subunits. We use a rigid flow cell to inject a solution of the coat protein of bacteriophage MS2 over multiple MS2 RNA strands that are tethered to a microscope coverslip by specific DNA linkages. Using an interferometric detection scheme, we measure changes in the intensity of light scattered from the proteins while they are assembling around each RNA. The low photodamage afforded by elastic scattering enables high illumination intensities and temporal resolutions down to 1 ms, while 3D-active stabilization of the microscope extends the measurement duration to 600 s or longer. With this wide range of timescales, we find that the assembly is characterized by an exponential distribution of wait times preceding a rapid growth phase, suggesting that the pathway under the conditions we investigate is nucleation followed by growth. Because the method can measure the assembly of many individual capsids in parallel, from start to finish, it offers a direct view of the self-assembly process not accessible to bulk scattering or spectroscopic techniques. It can be adapted to study the assembly of other viruses, biomolecular assemblies, and synthetic nanostructures.

 

Title:
An Analytical Portrait of Binary Mergers in Hierarchical Triple Systems
Authors:
Randall, Lisa; Xianyu, Zhong-Zhi
Publication:
eprint arXiv:1802.05718
Publication Date:
02/2018
Origin:
ARXIV
Keywords:
General Relativity and Quantum Cosmology, Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Phenomenology, High Energy Physics - Theory
Comment:
35 pages
Bibliographic Code:
2018arXiv180205718R

Abstract

With better statistics and precision, eccentricity could prove to be a useful tool for understanding the origin and environment of binary black holes. Hierarchical triples in particular, which are abundant in globular clusters and galactic nuclei, could generate observably large eccentricity at LIGO and future gravitational wave detectors. Measuring the eccentricity distribution accurately could help us probe the background and the formation of the mergers. In this paper we continue our previous investigation and improve our semi-analytical description of eccentricity distribution of mergers in galactic nuclei and other hierarchical triple systems. Our result, which further reduces the reliance on numerical simulations, could be useful for statistically distinguishing different formation channels of observed binary mergers.

 

Title:
Light, the universe, and everything -- 12 Herculean tasks for quantum cowboys and black diamond skiers
Authors:
Agarwal, Girish; Allen, Roland; Bezdekova, Iva; Walsworth, Ronald;... and 28 coauthors
Publication:
eprint arXiv:1802.06110
Publication Date:
02/2018
Origin:
ARXIV
Keywords:
Quantum Physics, Condensed Matter - Other Condensed Matter, Physics - Optics
Comment:
A review of the leading topics in quantum optics and related areas. Accepted for publication in J. Modern Optics (42 figures, 74 pages)
Bibliographic Code:
2018arXiv180206110A

Abstract

The Winter Colloquium on the Physics of Quantum Electronics (PQE) has been a seminal force in quantum optics and related areas since 1971. It is rather mindboggling to recognize how the concepts presented at these conferences have transformed scientific understanding and human society. In January, 2017, the participants of PQE were asked to consider the equally important prospects for the future, and to formulate a set of questions representing some of the greatest aspirations in this broad field. The result is this multi-authored paper, in which many of the world's leading experts address the following fundamental questions: (1) What is the future of gravitational wave astronomy? (2) Are there new quantum phases of matter away from equilibrium that can be found and exploited - such as the time crystal? (3) Quantum theory in uncharted territory: What can we learn? (4) What are the ultimate limits for laser photon energies? (5) What are the ultimate limits to temporal, spatial, and optical resolution? (6) What novel roles will atoms play in technology? (7) What applications lie ahead for nitrogen-vacancy centers in diamond? (8) What is the future of quantum coherence, squeezing, and entanglement for enhanced superresolution and sensing? (9) How can we solve (some of) humanity's biggest problems through new quantum technologies? (10) What new understanding of materials and biological molecules will result from their dynamical characterization with free electron lasers? (11) What new technologies and fundamental discoveries might quantum optics achieve by the end of this century? (12) What novel topological structures can be created and employed in quantum optics?

 

Title:
Seiberg-Witten differential via primitive forms
Authors:
Li, Si; Xie, Dan; Yau, Shing-Tung
Publication:
eprint arXiv:1802.06751
Publication Date:
02/2018
Origin:
ARXIV
Keywords:
High Energy Physics - Theory, Mathematical Physics, Mathematics - Algebraic Geometry
Comment:
24 pages
Bibliographic Code:
2018arXiv180206751L

Abstract

Three-fold quasi-homogeneous isolated rational singularity is argued to define a four dimensional $\mathcal{N}=2$ SCFT. The Seiberg-Witten geometry is built on the mini-versal deformation of the singularity. We argue in this paper that the corresponding Seiberg-Witten differential is given by the Gelfand-Leray form of K. Saito's primitive form. Our result also extends the Seiberg-Witten solution to include irrelevant deformations.

 

Title:
Probing sub-GeV Dark Matter-Baryon Scattering with Cosmological Observables
Authors:
Xu, Weishuang Linda; Dvorkin, Cora; Chael, Andrew
Publication:
eprint arXiv:1802.06788
Publication Date:
02/2018
Origin:
ARXIV
Keywords:
Astrophysics - Cosmology and Nongalactic Astrophysics, High Energy Physics - Phenomenology
Comment:
15 pages, 12 figures. References added, additional data sets included. Updated results that include high-ell polarization data (for the negative-n scenarios) due to a corrupted file
Bibliographic Code:
2018arXiv180206788X

Abstract

We derive new limits on the elastic scattering cross-section between baryons and dark matter using Cosmic Microwave Background data from the Planck satellite and measurements of the Lyman-alpha forest flux power spectrum from the Sloan Digital Sky Survey. Our analysis addresses generic cross sections of the form $\sigma\propto v^n$, where v is the dark matter-baryon relative velocity, allowing for constraints on the cross section independent of specific particle physics models. We include high-$\ell$ polarization data from Planck in our analysis, improving over previous constraints. We apply a more careful treatment of dark matter thermal evolution than previously done, allowing us to extend our constraints down to dark matter masses of $\sim$MeV. We show in this work that cosmological probes are complementary to current direct detection and astrophysical searches.

 

Title:
Readout Of Singlet-Triplet Qubits At Large Magnetic Field Gradients
Authors:
Orona, Lucas A.; Nichol, John M.; Harvey, Shannon P.; Bøttcher, Charlotte G. L.; Fallahi, Saeed; Gardner, Geoffrey C.; Manfra, Michael J.; Yacoby, Amir
Publication:
eprint arXiv:1802.07627
Publication Date:
02/2018
Origin:
ARXIV
Keywords:
Condensed Matter - Mesoscale and Nanoscale Physics
Bibliographic Code:
2018arXiv180207627O

Abstract

Visibility of singlet-triplet qubit readout is reduced to almost zero in large magnetic field gradients due to relaxation processes. Here we present a new readout technique that is robust against relaxation and allows for measurement when previously studied methods fail. This technique maps the qubit onto spin states that are immune to relaxation using a spin dependent electron tunneling process between the qubit and the lead. We probe this readout's performance as a function of magnetic field gradient and applied magnetic field, and optimize the pulse applied to the qubit through experiment and simulation.

 

Title:
Additional contributions from: Nobel Symposium 162 - Microfluidics
Authors:
Löfås, Stefan; Herr, Amy E.; Qin, Jianhua; Knowles, Tuomas; Kitamori, Takehiko; Lu, Hang; Beebe, David J.; Han, Jongyoon; Landers, James; Manz, Andreas; Zengerle, Roland; Weitz, David A.; Elf, Johan; Laurell, Thomas
Publication:
eprint arXiv:1802.08565
Publication Date:
02/2018
Origin:
ARXIV
Keywords:
Physics - Fluid Dynamics, Quantitative Biology - Other Quantitative Biology
Comment:
Nobel Symposium 162, Stockholm, Sweden, 2017 arXiv:1712.08369v1 Report-no: Nobel162/2017/00
Bibliographic Code:
2018arXiv180208565L

Abstract

Series of short contributions that are part of Nobel Symposium 162 - Microfluidics arXiv:1712.08369.

 

Title:
Emergence and the Swampland Conjectures
Authors:
Heidenreich, Ben; Reece, Matthew; Rudelius, Tom
Publication:
eprint arXiv:1802.08698
Publication Date:
02/2018
Origin:
ARXIV
Keywords:
High Energy Physics - Theory
Comment:
6 pages
Bibliographic Code:
2018arXiv180208698H

Abstract

The Ooguri-Vafa Swampland Conjectures claim that in any consistent theory of quantum gravity, when venturing to large distances in scalar field space, a tower of particles will become light at a rate that is exponential in the field space distance. We provide a novel viewpoint on this claim: if we assume that a tower of states becomes light near a particular point in field space, and we further demand that loop corrections drive both gravity and the scalar to strong coupling at a common energy scale, then the requirement that the particles become light exponentially fast in the field-space distance in Planck units follows automatically. Furthermore, the same assumption of a common strong-coupling scale for scalar fields and gravitons implies that when a scalar field evolves over a super-Planckian distance, the average particle mass changes by an amount of order the cutoff energy. This supports earlier suggestions that significantly super-Planckian excursions in field space cannot be described within a single effective field theory. We comment on the relationship of our results to the Weak Gravity Conjecture.

 

Title:
Ionization Electron Signal Processing in Single Phase LArTPCs I. Algorithm Description and Quantitative Evaluation with MicroBooNE Simulation
Authors:
MicroBooNE collaboration; Adams, C.; An, R.; Anthony, J.; Asaadi, J.;... Guenette, R.;... ; and 164 coauthors
Publication:
eprint arXiv:1802.08709
Publication Date:
02/2018
Origin:
ARXIV
Keywords:
Physics - Instrumentation and Detectors, High Energy Physics - Experiment, Nuclear Experiment
Comment:
60 pages, 36 figures. The second part of this work can be found at arXiv:1804.02583
Bibliographic Code:
2018arXiv180208709M

Abstract

We describe the concept and procedure of drifted-charge extraction developed in the MicroBooNE experiment, a single-phase liquid argon time projection chamber (LArTPC). This technique converts the raw digitized TPC waveform to the number of ionization electrons passing through a wire plane at a given time. A robust recovery of the number of ionization electrons from both induction and collection anode wire planes will augment the 3D reconstruction, and is particularly important for tomographic reconstruction algorithms. A number of building blocks of the overall procedure are described. The performance of the signal processing is quantitatively evaluated by comparing extracted charge with the true charge through a detailed TPC detector simulation taking into account position-dependent induced current inside a single wire region and across multiple wires. Some areas for further improvement of the performance of the charge extraction procedure are also discussed.

 

Title:
Thermoelectric signatures of the electron-phonon fluid in PtSn4
Authors:
Fu, Chenguang; Scaffidi, Thomas; Waissman, Jonah; Sun, Yan; Saha, Rana; Watzman, Sarah J.; Srivastava, Abhay K.; Li, Guowei; Schnelle, Walter; Werner, Peter; Kamminga, Machteld E.; Sachdev, Subir; Parkin, Stuart S. P.; Hartnoll, Sean A.; Felser, Claudia; Gooth, Johannes
Publication:
eprint arXiv:1802.09468
Publication Date:
02/2018
Origin:
ARXIV
Keywords:
Condensed Matter - Materials Science
Bibliographic Code:
2018arXiv180209468F

Abstract

In most materials, transport can be described by the motion of distinct species of quasiparticles, such as electrons and phonons. Strong interactions between quasiparticles, however, can lead to collective behaviour, including the possibility of viscous hydrodynamic flow. In the case of electrons and phonons, an electron-phonon fluid is expected to exhibit strong phonon-drag transport signatures and an anomalously low thermal conductivity. The Dirac semi-metal PtSn4 has a very low resistivity at low temperatures and shows a pronounced phonon drag peak in the low temperature thermopower; it is therefore an excellent candidate for hosting a hydrodynamic electron-phonon fluid. Here we report measurements of the temperature and magnetic field dependence of the longitudinal and Hall electrical resistivities, the thermopower and the thermal conductivity of PtSn4. We confirm a phonon drag peak in the thermopower near 14 K and observe a concurrent breakdown of the Lorenz ratio below the Sommerfeld value. Both of these facts are expected for an electron-phonon fluid with a quasi-conserved total momentum. A hierarchy between momentum-conserving and momentum-relaxing scattering timescales is corroborated through measurements of the magnetic field dependence of the electrical and Hall resistivity and of the thermal conductivity. These results show that PtSn4 exhibits key features of hydrodynamic transport.

 

Title:
Emergent Multi-flavor QED3 at the Plateau Transition between Fractional Chern Insulators: Applications to graphene heterostructures
Authors:
Lee, Jong Yeon; Wang, Chong; Zaletel, Michael P.; Vishwanath, Ashvin; He, Yin-Chen
Publication:
eprint arXiv:1802.09538
Publication Date:
02/2018
Origin:
ARXIV
Keywords:
Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Mesoscale and Nanoscale Physics, High Energy Physics - Theory
Comment:
16 pages + refs, 6 figures
Bibliographic Code:
2018arXiv180209538L

Abstract

Recent experiments in graphene heterostructures have observed Chern insulators - integer and fractional Quantum Hall states made possible by a periodic substrate potential. Here we study theoretically the competition between different Chern insulators, which can be tuned by the amplitude of the periodic potential, leads to a new family of quantum critical points described by QED$_3$-Chern-Simons theory. At these critical points, $N_f$ flavors of Dirac fermions interact through an emergent U$(1)$ gauge theory at Chern-Simons level $K$, and remarkably, the entire family (with any $N_f$ or $K$) can be realized at special values of the external magnetic field. Transitions between particle-hole conjugate Jain states realize "pure" QED$_3$ in which multiple flavors of Dirac fermion interact with a Maxwell U$(1)$ gauge field. The multi-flavor nature of the critical point leads to an emergent SU$(N_f)$ symmetry. Specifically, at the transition from a $\nu=$1/3 to 2/3 quantum Hall state, the emergent SU(3) symmetry predicts an octet of charge density waves with enhanced susceptibilities, which is verified by DMRG numerical simulations on microscopic models applicable to graphene heterostructures. We propose experiments on Chern insulators that could resolve open questions in the study of 2+1 dimensional conformal field theories and test recent duality inspired conjectures.

 

Title:
A Cascade Leading to the Emergence of Small Structures in Vortex Ring Collisions
Authors:
McKeown, Ryan; Ostilla Monico, Rodolfo; Pumir, Alain; Brenner, Michael P.; Rubinstein, Shmuel M.
Publication:
eprint arXiv:1802.09973
Publication Date:
02/2018
Origin:
ARXIV
Keywords:
Physics - Fluid Dynamics
Comment:
7 pages, 6 figures, 6 videos
Bibliographic Code:
2018arXiv180209973M

Abstract

Our understanding of turbulence still lacks a mechanistic description for how kinetic energy, added into a flow at large scales, cascades to smaller and smaller scales until it is eventually dissipated via molecular fluctuations. We experimentally show that the head-on collision of two laminar vortex rings into a turbulent cloud uncovers the first direct evidence of a self-similar cascade. When the coherent vortex rings approach each other, the vortex cores deform into tent-like structures, and the mutual strain causes them to locally flatten into extremely thin vortex sheets. These sheets then break down into smaller secondary vortex filaments, which themselves rapidly flatten and break down into even smaller tertiary filaments. By performing numerical simulations of the full Navier-Stokes equations, we also resolve one iteration of this cascade and highlight the subtle role that viscosity must play in the puncturing of a vortex sheet. The concurrence of this observed iterative cascade of instabilities with those of recent theoretical predictions could provide further insights into the latent dynamical mechanisms of turbulent flows, namely whether singularities, or blow-ups, exist in the equations governing fluid motion.

 

Title:
CW and CCW Conformations of the E. coli Flagellar Motor C-Ring Evaluated by Fluorescence Anisotropy
Authors:
Hosu, Basarab G.; Berg, Howard C.
Publication:
Biophysical Journal, vol. 114, issue 3, pp. 641-649
Publication Date:
02/2018
Origin:
CROSSREF
DOI:
10.1016/j.bpj.2017.12.001
Bibliographic Code:
2018BpJ...114..641H

Abstract

Not Available

 

Title:
A Molecular Rack and Pinion Actuates a Cell-Surface Adhesin and Enables Bacterial Gliding Motility
Authors:
Shrivastava, Abhishek; Berg, Howard C.
Publication:
Biophysical Journal, vol. 114, issue 3, p. 372a
Publication Date:
02/2018
Origin:
CROSSREF
DOI:
10.1016/j.bpj.2017.11.2060
Bibliographic Code:
2018BpJ...114Q.372S

Abstract

Not Available

 

Title:
High-throughput Rotation Tracking using DNA Origami Rotors
Authors:
Kosuri, Pallav; Altheimer, Benjamin; Dai, Mingjie; Yin, Peng; Zhuang, Xiaowei
Publication:
Biophysical Journal, vol. 114, issue 3, p. 389a
Publication Date:
02/2018
Origin:
CROSSREF
DOI:
10.1016/j.bpj.2017.11.2154
Bibliographic Code:
2018BpJ...114Q.389K

Abstract

Not Available

 

Title:
Lipid-Gel Model of Biological Membranes
Authors:
Shi, Zheng; Graber, Zachary T.; Baumgart, Tobias; Stone, Howard A.; Cohen, Adam E.
Publication:
Biophysical Journal, vol. 114, issue 3, p. 115a
Publication Date:
02/2018
Origin:
CROSSREF
DOI:
10.1016/j.bpj.2017.11.662
Bibliographic Code:
2018BpJ...114R.115S

Abstract

Not Available

 

Title:
Search for new phenomena in high-mass final states with a photon and a jet from pp collisions at √{s} = 13 TeV with the ATLAS detector
Authors:
Aaboud, M.; Aad, G.; Abbott, B.; Abdinov, O.;... Franklin, M.;... Huth, J.;... Morii, M.;... and 2886 coauthors
Publication:
The European Physical Journal C, Volume 78, Issue 2, article id.102, 25 pp. (EPJC Homepage)
Publication Date:
02/2018
Origin:
SPRINGER
Abstract Copyright:
(c) 2018: CERN for the benefit of the ATLAS collaboration
DOI:
10.1140/epjc/s10052-018-5553-2
Bibliographic Code:
2018EPJC...78..102A

Abstract

A search is performed for new phenomena in events having a photon with high transverse momentum and a jet collected in 36.7 {fb}^{-1} of proton-proton collisions at a centre-of-mass energy of √{s} = 13 TeV recorded with the ATLAS detector at the Large Hadron Collider. The invariant mass distribution of the leading photon and jet is examined to look for the resonant production of new particles or the presence of new high-mass states beyond the Standard Model. No significant deviation from the background-only hypothesis is observed and cross-section limits for generic Gaussian-shaped resonances are extracted. Excited quarks hypothesized in quark compositeness models and high-mass states predicted in quantum black hole models with extra dimensions are also examined in the analysis. The observed data exclude, at 95% confidence level, the mass range below 5.3 TeV for excited quarks and 7.1 TeV (4.4 TeV) for quantum black holes in the Arkani-Hamed-Dimopoulos-Dvali (Randall-Sundrum) model with six (one) extra dimensions.

 

Title:
Measurement of the W-boson mass in pp collisions at √{s}=7 TeV with the ATLAS detector
Authors:
Aaboud, M.; Aad, G.; Abbott, B.; Abdallah, J.;... Franklin, M.;... Huth, J.;... Morii, M.;... and 2834 coauthors
Publication:
The European Physical Journal C, Volume 78, Issue 2, article id.110, 61 pp. (EPJC Homepage)
Publication Date:
02/2018
Origin:
SPRINGER
Abstract Copyright:
(c) 2018: CERN for the benefit of the ATLAS collaboration
DOI:
10.1140/epjc/s10052-017-5475-4
Bibliographic Code:
2018EPJC...78..110A

Abstract

A measurement of the mass of the W boson is presented based on proton-proton collision data recorded in 2011 at a centre-of-mass energy of 7 TeV with the ATLAS detector at the LHC, and corresponding to 4.6 fb^{-1} of integrated luminosity. The selected data sample consists of 7.8× 10^6 candidates in the W→ μ ν channel and 5.9× 10^6 candidates in the W→ e ν channel. The W-boson mass is obtained from template fits to the reconstructed distributions of the charged lepton transverse momentum and of the W boson transverse mass in the electron and muon decay channels, yielding m_W = 80370&± 7 ( {stat.}) ± 11 ( {exp. syst.}) ± 14 ( {mod. syst.}) {MeV} = 80370± 19 {MeV}, where the first uncertainty is statistical, the second corresponds to the experimental systematic uncertainty, and the third to the physics-modelling systematic uncertainty. A measurement of the mass difference between the W^+ and W^- bosons yields m_{W^+}-m_{W^-} = - 29 ± 28 MeV.

 

Title:
Direct top-quark decay width measurement in the \varvec{t\bar{t}} lepton+jets channel at √{s}=8 {TeV} with the ATLAS experiment
Authors:
Aaboud, M.; Aad, G.; Abbott, B.; Abdinov, O.;... Franklin, M.;... Huth, J.;... Morii, M.;... and 2893 coauthors
Publication:
The European Physical Journal C, Volume 78, Issue 2, article id.129, 30 pp. (EPJC Homepage)
Publication Date:
02/2018
Origin:
SPRINGER
Abstract Copyright:
(c) 2018: CERN for the benefit of the ATLAS collaboration
DOI:
10.1140/epjc/s10052-018-5595-5
Bibliographic Code:
2018EPJC...78..129A

Abstract

This paper presents a direct measurement of the decay width of the top quark using t\bar{t} events in the lepton+jets final state. The data sample was collected by the ATLAS detector at the LHC in proton-proton collisions at a centre-of-mass energy of 8 TeV and corresponds to an integrated luminosity of 20.2 fb^{-1}. The decay width of the top quark is measured using a template fit to distributions of kinematic observables associated with the hadronically and semileptonically decaying top quarks. The result, Γ _t = 1.76 ± 0.33 ( {stat.}) ^{+0.79}_{-0.68} ( {syst.}) {GeV} for a top-quark mass of 172.5 GeV, is consistent with the prediction of the Standard Model.

 

Title:
Measurement of longitudinal flow decorrelations in Pb+Pb collisions at √{s_{ {NN}}}=2.76 and 5.02 TeV with the ATLAS detector
Authors:
Aaboud, M.; Aad, G.; Abbott, B.; Abdinov, O.;... Franklin, M.;... Huth, J.;... Morii, M.;... and 2895 coauthors
Publication:
The European Physical Journal C, Volume 78, Issue 2, article id.142, 37 pp. (EPJC Homepage)
Publication Date:
02/2018
Origin:
SPRINGER
Abstract Copyright:
(c) 2018: CERN for the benefit of the ATLAS collaboration
DOI:
10.1140/epjc/s10052-018-5605-7
Bibliographic Code:
2018EPJC...78..142A

Abstract

Measurements of longitudinal flow correlations are presented for charged particles in the pseudorapidity range |η |<2.4 using 7 and 470 μ b^{-1} of Pb+Pb collisions at √{s_{ {NN}}}=2.76 and 5.02 TeV, respectively, recorded by the ATLAS detector at the LHC. It is found that the correlation between the harmonic flow coefficients v_n measured in two separated η intervals does not factorise into the product of single-particle coefficients, and this breaking of factorisation, or flow decorrelation, increases linearly with the η separation between the intervals. The flow decorrelation is stronger at 2.76 TeV than at 5.02 TeV. Higher-order moments of the correlations are also measured, and the corresponding linear coefficients for the k{ {th}}-moment of the v_n are found to be proportional to k for v_3, but not for v_2. The decorrelation effect is separated into contributions from the magnitude of v_n and the event-plane orientation, each as a function of η . These two contributions are found to be comparable. The longitudinal flow correlations are also measured between v_n of different order in n. The decorrelations of v_2 and v_3 are found to be independent of each other, while the decorrelations of v_4 and v_5 are found to be driven by the nonlinear contribution from v_2^2 and v_2v_3, respectively.

 

Title:
Search for the direct production of charginos and neutralinos in final states with tau leptons in √{s} = 13 TeV pp collisions with the ATLAS detector
Authors:
Aaboud, M.; Aad, G.; Abbott, B.; Abdinov, O.;... Franklin, M.;... Huth, J.;... Morii, M.;... and 2875 coauthors
Publication:
The European Physical Journal C, Volume 78, Issue 2, article id.154, 33 pp. (EPJC Homepage)
Publication Date:
02/2018
Origin:
SPRINGER
Abstract Copyright:
(c) 2018: CERN for the benefit of the ATLAS collaboration
DOI:
10.1140/epjc/s10052-018-5583-9
Bibliographic Code:
2018EPJC...78..154A

Abstract

A search for the direct production of charginos and neutralinos in final states with at least two hadronically decaying tau leptons is presented. The analysis uses a dataset of pp collisions corresponding to an integrated luminosity of 36.1 fb^{-1}, recorded with the ATLAS detector at the Large Hadron Collider at a centre-of-mass energy of 13 TeV. No significant deviation from the expected Standard Model background is observed. Limits are derived in scenarios of (?) pair production and of (?) and (?) production in simplified models where the neutralinos and charginos decay solely via intermediate left-handed staus and tau sneutrinos, and the mass of the \tilde{τ }_L state is set to be halfway between the masses of the (?) and the (?). Chargino masses up to 630 GeV are excluded at 95% confidence level in the scenario of direct production of (?) for a massless (?). Common (?) and (?) masses up to 760 GeV are excluded in the case of production of (?) and (?) assuming a massless (?). Exclusion limits for additional benchmark scenarios with large and small mass-splitting between the (?) and the (?) are also studied by varying the \tilde{τ }_L mass between the masses of the (?) and the (?).

 

Title:
Measurement of τ polarisation in Z/γ ^{*}→ τ τ decays in proton-proton collisions at √{s}=8 TeV with the ATLAS detector
Authors:
Aaboud, M.; Aad, G.; Abbott, B.; Abdinov, O.;... Franklin, M.;... Huth, J.;... Morii, M.;... and 2889 coauthors
Publication:
The European Physical Journal C, Volume 78, Issue 2, article id.163, 30 pp. (EPJC Homepage)
Publication Date:
02/2018
Origin:
SPRINGER
Abstract Copyright:
(c) 2018: CERN for the benefit of the ATLAS collaboration
DOI:
10.1140/epjc/s10052-018-5619-1
Bibliographic Code:
2018EPJC...78..163A

Abstract

This paper presents a measurement of the polarisation of τ leptons produced in Z/γ ^{*}→ τ τ decays which is performed with a dataset of proton—proton collisions at √{s}=8 TeV, corresponding to an integrated luminosity of 20.2 fb^{-1} recorded with the ATLAS detector at the LHC in 2012. The Z/γ ^{*}→ τ τ decays are reconstructed from a hadronically decaying τ lepton with a single charged particle in the final state, accompanied by a τ lepton that decays leptonically. The τ polarisation is inferred from the relative fraction of energy carried by charged and neutral hadrons in the hadronic τ decays. The polarisation is measured in a fiducial region that corresponds to the kinematic region accessible to this analysis. The τ polarisation extracted over the full phase space within the Z/γ ^{*} mass range of 66 < m_{Z/γ ^{*}} < 116 GeV is found to be P_{τ } =-0.14 ± 0.02 ( {stat}) ± 0.04 ( {syst}). It is in agreement with the Standard Model prediction of P_{τ } =-0.1517 ± 0.0019, which is obtained from the ALPGEN event generator interfaced with the PYTHIA 6 parton shower modelling and the TAUOLA τ decay library.

 

Title:
Experimental targets for photon couplings of the QCD axion
Authors:
Agrawal, Prateek; Fan, JiJi; Reece, Matthew; Wang, Lian-Tao
Publication:
Journal of High Energy Physics, Volume 2018, Issue 2, article id.6, 25 pp.
Publication Date:
02/2018
Origin:
SPRINGER
Keywords:
Beyond Standard Model, Nonperturbative Effects
Abstract Copyright:
(c) 2018: The Author(s)
DOI:
10.1007/JHEP02(2018)006
Bibliographic Code:
2018JHEP...02..006A

Abstract

The QCD axion's coupling to photons is often assumed to lie in a narrow band as a function of the axion mass. We demonstrate that several simple mechanisms, in addition to the photophilic clockwork axion already in the literature, can significantly extend the allowed range of couplings. Some mechanisms we present generalize the KNP alignment scenario, widely studied as a model of inflation, to the phenomenology of a QCD axion. In particular we present KSVZ-like realizations of two-axion KNP alignment and of the clockwork mechanism. Such a "confinement tower" realization of clockwork may prove useful in a variety of model-building contexts. We also show that kinetic mixing of the QCD axion with a lighter axion-like particle can dramatically alter the QCD axion's coupling to photons, differing from the other models we present by allowing non-quantized couplings. The simple models that we present fully cover the range of axion-photon couplings that could be probed by experiments. They motivate growing axion detection efforts over a wide space of masses and couplings.

 

Title:
Negative branes, supergroups and the signature of spacetime
Authors:
Dijkgraaf, Robbert; Heidenreich, Ben; Jefferson, Patrick; Vafa, Cumrun
Publication:
Journal of High Energy Physics, Volume 2018, Issue 2, article id.50, 63 pp.
Publication Date:
02/2018
Origin:
SPRINGER
Keywords:
D-branes, Gauge Symmetry, String Duality, AdS-CFT Correspondence
Abstract Copyright:
(c) 2018: The Author(s)
DOI:
10.1007/JHEP02(2018)050
Bibliographic Code:
2018JHEP...02..050D

Abstract

We study the realization of supergroup gauge theories using negative branes in string theory. We show that negative branes are intimately connected with the possibility of timelike compactification and exotic spacetime signatures previously studied by Hull. Isolated negative branes dynamically generate a change in spacetime signature near their worldvolumes, and are related by string dualities to a smooth M-theory geometry with closed timelike curves. Using negative D3-branes, we show that SU(0| N) supergroup theories are holographically dual to an exotic variant of type IIB string theory on {dS}_{3,2}× {\overline{S}}^5 , for which the emergent dimensions are timelike. Using branes, mirror symmetry and Nekrasov's instanton calculus, all of which agree, we derive the Seiberg-Witten curve for N=2 SU( N | M ) gauge theories. Together with our exploration of holography and string dualities for negative branes, this suggests that supergroup gauge theories may be non-perturbatively well-defined objects, though several puzzles remain.

 

Title:
Soft factorization in QED from 2D Kac-Moody symmetry
Authors:
Nande, Anjalika; Pate, Monica; Strominger, Andrew
Publication:
Journal of High Energy Physics, Volume 2018, Issue 2, article id.79, 17 pp.
Publication Date:
02/2018
Origin:
SPRINGER
Keywords:
Conformal Field Theory, Gauge Symmetry, Scattering Amplitudes
Abstract Copyright:
(c) 2018: The Author(s)
DOI:
10.1007/JHEP02(2018)079
Bibliographic Code:
2018JHEP...02..079N

Abstract

The soft factorization theorem for 4D abelian gauge theory states that the S -matrix factorizes into soft and hard parts, with the universal soft part containing all soft and collinear poles. Similarly, correlation functions on the sphere in a 2D CFT with a U(1) Kac-Moody current algebra factorize into current algebra and non-current algebra factors, with the current algebra factor fully determined by its pole structure. In this paper, we show that these 4D and 2D factorizations are mathematically the same phenomena. The soft `t Hooft-Wilson lines and soft photons are realized as a complexified 2D current algebra on the celestial sphere at null infinity. The current algebra level is determined by the cusp anomalous dimension. The associated complex U(1) boson lives on a torus whose modular parameter is τ =2π i/e^2+θ /2π . The correlators of this 2D current algebra fully reproduce the known soft part of the 4D S -matrix, as well as a conjectured generalization involving magnetic charges.

 

Title:
6d string chains
Authors:
Gadde, Abhijit; Haghighat, Babak; Kim, Joonho; Kim, Seok; Lockhart, Guglielmo; Vafa, Cumrun
Publication:
Journal of High Energy Physics, Volume 2018, Issue 2, article id.143, 32 pp.
Publication Date:
02/2018
Origin:
SPRINGER
Keywords:
Duality in Gauge Field Theories, F-Theory, Field Theories in Higher Dimensions, Solitons Monopoles and Instantons
Abstract Copyright:
(c) 2018: The Author(s)
DOI:
10.1007/JHEP02(2018)143
Bibliographic Code:
2018JHEP...02..143G

Abstract

We consider bound states of strings which arise in 6d (1,0) SCFTs that are realized in F-theory in terms of linear chains of spheres with negative self-intersections 1,2, and 4. These include the strings associated to N small E 8 instantons, as well as the ones associated to M5 branes probing A and D type singularities in M-theory or D5 branes probing ADE singularities in Type IIB string theory. We find that these bound states of strings admit (0,4) supersymmetric quiver descriptions and show how one can compute their elliptic genera.

 

Title:
Gold Nanorods Conjugated Porous Silicon Nanoparticles Encapsulated in Calcium Alginate Nano Hydrogels Using Microemulsion Templates
Authors:
Zhang, Hongbo; Zhu, Yueqi; Qu, Liangliang; Wu, Huayin; Kong, Haixin; Yang, Zhou; Chen, Dong; Mäkilä, Ermei; Salonen, Jarno; Santos, Hélder A.; Hai, Mingtan; Weitz, David A.
Affiliation:
AF(0000-0003-1229-3739), AG(0000-0002-8904-9307), AI(0000-0002-5245-742X), AJ(0000-0001-7850-6309), AL(0000-0001-6678-5208)
Publication:
Nano Letters, vol. 18, issue 2, pp. 1448-1453
Publication Date:
02/2018
Origin:
CROSSREF
DOI:
10.1021/acs.nanolett.7b05210
Bibliographic Code:
2018NanoL..18.1448Z

Abstract

Not Available

 

Title:
Electrical control of charged carriers and excitons in atomically thin materials
Authors:
Wang, Ke; De Greve, Kristiaan; Jauregui, Luis A.; Sushko, Andrey; High, Alexander; Zhou, You; Scuri, Giovanni; Taniguchi, Takashi; Watanabe, Kenji; Lukin, Mikhail D.; Park, Hongkun; Kim, Philip
Publication:
Nature Nanotechnology, Volume 13, Issue 2, p.128-132
Publication Date:
02/2018
Origin:
NATURE
Abstract Copyright:
2018: The Author(s)
DOI:
10.1038/s41565-017-0030-x
Bibliographic Code:
2018NatNa..13..128W

Abstract

Electrical confinement and manipulation of charge carriers in semiconducting nanostructures are essential for realizing functional quantum electronic devices1-3. The unique band structure4-7 of atomically thin transition metal dichalcogenides (TMDs) offers a new route towards realizing novel 2D quantum electronic devices, such as valleytronic devices and valley-spin qubits8. 2D TMDs also provide a platform for novel quantum optoelectronic devices9-11 due to their large exciton binding energy12,13. However, controlled confinement and manipulation of electronic and excitonic excitations in TMD nanostructures have been technically challenging due to the prevailing disorder in the material, preventing accurate experimental control of local confinement and tunnel couplings14-16. Here we demonstrate a novel method for creating high-quality heterostructures composed of atomically thin materials that allows for efficient electrical control of excitations. Specifically, we demonstrate quantum transport in the gate-defined, quantum-confined region, observing spin-valley locked quantized conductance in quantum point contacts. We also realize gate-controlled Coulomb blockade associated with confinement of electrons and demonstrate electrical control over charged excitons with tunable local confinement potentials and tunnel couplings. Our work provides a basis for novel quantum opto-electronic devices based on manipulation of charged carriers and excitons.

 

Title:
Double light-cone dynamics establish thermal states in integrable 1D Bose gases
Authors:
Langen, T.; Schweigler, T.; Demler, E.; Schmiedmayer, J.
Publication:
New Journal of Physics, Volume 20, Issue 2, article id. 023034 (2018).
Publication Date:
02/2018
Origin:
IOP
DOI:
10.1088/1367-2630/aaaaa5
Bibliographic Code:
2018NJPh...20b3034L

Abstract

We theoretically investigate the non-equilibrium dynamics in a quenched pair of one-dimensional Bose gases with density imbalance. We describe the system using its low-energy effective theory, the Luttinger liquid model. In this framework the system shows strictly integrable relaxation dynamics via dephasing of its approximate many-body eigenstates. In the balanced case, this leads to the well-known light-cone-like establishment of a prethermalized state, which can be described by a generalized Gibbs ensemble. In the imbalanced case the integrable dephasing leads to a state that, counter-intuitively, closely resembles a thermal equilibrium state. The approach to this state is characterized by two separate light-cone dynamics with distinct characteristic velocities. This behavior is a result of the fact that in the imbalanced case observables are not aligned with the conserved quantities of the integrable system. We discuss a concrete experimental realization to study this effect using matterwave interferometry and many-body revivals on an atom chip.

 

itle:
Search for diboson resonances with boson-tagged jets in pp collisions at √{ s } = 13 TeV with the ATLAS detector
Authors:
Aaboud, M.; Aad, G.; Abbott, B.; Abdinov, O.;... Franklin, M.;... Huth, J.;... Morii, M.;... and 2887 coauthors
Publication:
Physics Letters B, Volume 777, p. 91-113.
Publication Date:
02/2018
Origin:
ELSEVIER
Abstract Copyright:
(c) 2018 Elsevier Science B.V. All rights reserved.
DOI:
10.1016/j.physletb.2017.12.011
Bibliographic Code:
2018PhLB..777...91A

Abstract

Narrow resonances decaying into WW, WZ or ZZ boson pairs are searched for in 36.7 fb-1 of proton-proton collision data at a centre-of-mass energy of √{ s } = 13 TeV recorded with the ATLAS detector at the Large Hadron Collider in 2015 and 2016. The diboson system is reconstructed using pairs of large-radius jets with high transverse momentum and tagged as compatible with the hadronic decay of high-momentum W or Z bosons, using jet mass and substructure properties. The search is sensitive to diboson resonances with masses in the range 1.2-5.0 TeV. No significant excess is observed in any signal region. Exclusion limits are set at the 95% confidence level on the production cross section times branching ratio to dibosons for a range of theories beyond the Standard Model. Model-dependent lower limits on the mass of new gauge bosons are set, with the highest limit set at 3.5 TeV in the context of mass-degenerate resonances that couple predominantly to bosons.

 

Title:
Measurement of the exclusive γγ → μ+μ- process in proton-proton collisions at √{ s } = 13 TeV with the ATLAS detector
Authors:
Aaboud, M.; Aad, G.; Abbott, B.; Abdinov, O.;... and 2888 coauthors
Publication:
Physics Letters B, Volume 777, p. 303-323.
Publication Date:
02/2018
Origin:
ELSEVIER
Abstract Copyright:
(c) 2018 Elsevier Science B.V. All rights reserved.
DOI:
10.1016/j.physletb.2017.12.043
Bibliographic Code:
2018PhLB..777..303A

Abstract

The production of exclusive γγ →μ+μ- events in proton-proton collisions at a centre-of-mass energy of 13 TeV is measured with the ATLAS detector at the LHC, using data corresponding to an integrated luminosity of 3.2 fb-1. The measurement is performed for a dimuon invariant mass of 12GeV <m < μ+μ-

 

Title:
Theory of excitation of Rydberg polarons in an atomic quantum gas
Authors:
Schmidt, R.; Whalen, J. D.; Ding, R.; Camargo, F.; Woehl, G.; Yoshida, S.; Burgdörfer, J.; Dunning, F. B.; Demler, E.; Sadeghpour, H. R.; Killian, T. C.
Publication:
Physical Review A, Volume 97, Issue 2, id.022707 (PhRvA Homepage)
Publication Date:
02/2018
Origin:
APS
Abstract Copyright:
2018: American Physical Society
DOI:
10.1103/PhysRevA.97.022707
Bibliographic Code:
2018PhRvA..97b2707S

Abstract

We present a quantum many-body description of the excitation spectrum of Rydberg polarons in a Bose gas. The many-body Hamiltonian is solved with a functional determinant approach, and we extend this technique to describe Rydberg polarons of finite mass. Mean-field and classical descriptions of the spectrum are derived as approximations of the many-body theory. The various approaches are applied to experimental observations of polarons created by excitation of Rydberg atoms in a strontium Bose-Einstein condensate.

 

Title:
Many-body interferometry of magnetic polaron dynamics
Authors:
Ashida, Yuto; Schmidt, Richard; Tarruell, Leticia; Demler, Eugene
Publication:
Physical Review B, Volume 97, Issue 6, id.060302 (PhRvB Homepage)
Publication Date:
02/2018
Origin:
APS
Abstract Copyright:
2018: American Physical Society
DOI:
10.1103/PhysRevB.97.060302
Bibliographic Code:
2018PhRvB..97f0302A

Abstract

The physics of quantum impurities coupled to a many-body environment is among the most important paradigms of condensed-matter physics. In particular, the formation of polarons, quasiparticles dressed by the polarization cloud, is key to the understanding of transport, optical response, and induced interactions in a variety of materials. Despite recent remarkable developments in ultracold atoms and solid-state materials, the direct measurement of their ultimate building block, the polaron cloud, has remained a fundamental challenge. We propose and analyze a platform to probe time-resolved dynamics of polaron-cloud formation with an interferometric protocol. We consider an impurity atom immersed in a two-component Bose-Einstein condensate where the impurity generates spin-wave excitations that can be directly measured by the Ramsey interference of surrounding atoms. The dressing by spin waves leads to the formation of magnetic polarons and reveals a unique interplay between few- and many-body physics that is signified by single- and multi-frequency oscillatory dynamics corresponding to the formation of many-body bound states. Finally, we discuss concrete experimental implementations in ultracold atoms.

 

Title:
Topology-optimized dual-polarization Dirac cones
Authors:
Lin, Zin; Christakis, Lysander; Li, Yang; Mazur, Eric; Rodriguez, Alejandro W.; Lončar, Marko
Publication:
Physical Review B, Volume 97, Issue 8, id.081408 (PhRvB Homepage)
Publication Date:
02/2018
Origin:
APS
Abstract Copyright:
2018: American Physical Society
DOI:
10.1103/PhysRevB.97.081408
Bibliographic Code:
2018PhRvB..97h1408L

Abstract

We apply a large-scale computational technique, known as topology optimization, to the inverse design of photonic Dirac cones. In particular, we report on a variety of photonic crystal geometries, realizable in simple isotropic dielectric materials, which exhibit dual-polarization Dirac cones. We present photonic crystals of different symmetry types, such as fourfold and sixfold rotational symmetries, with Dirac cones at different points within the Brillouin zone. The demonstrated and related optimization techniques open avenues to band-structure engineering and manipulating the propagation of light in periodic media, with possible applications to exotic optical phenomena such as effective zero-index media and topological photonics.

 

Title:
Logarithmic singularities and quantum oscillations in magnetically doped topological insulators
Authors:
Nandi, D.; Sodemann, Inti; Shain, K.; Lee, G. H.; Huang, K.-F.; Chang, Cui-Zu; Ou, Yunbo; Lee, S. P.; Ward, J.; Moodera, J. S.; Kim, P.; Yacoby, A.
Publication:
Physical Review B, Volume 97, Issue 8, id.085151 (PhRvB Homepage)
Publication Date:
02/2018
Origin:
APS
Abstract Copyright:
2018: American Physical Society
DOI:
10.1103/PhysRevB.97.085151
Bibliographic Code:
2018PhRvB..97h5151N

Abstract

We report magnetotransport measurements on magnetically doped (Bi,Sb ) 2Te3 films grown by molecular beam epitaxy. In Hall bar devices, we observe logarithmic dependence of transport coefficients in temperature and bias voltage which can be understood to arise from electron-electron interaction corrections to the conductivity and self-heating. Submicron scale devices exhibit intriguing quantum oscillations at high magnetic fields with dependence on bias voltage. The observed quantum oscillations can be attributed to bulk and surface transport.

 

Title:
Measurement of long-range multiparticle azimuthal correlations with the subevent cumulant method in p p and p +Pb collisions with the ATLAS detector at the CERN Large Hadron Collider
Authors:
Aaboud, M.; Aad, G.; Abbott, B.; Abdinov, O.;... Franklin, M.;... Huth, J.;... Morii, M.;... and 2892 coauthors
Publication:
Physical Review C, Volume 97, Issue 2, id.024904 (PhRvC Homepage)
Publication Date:
02/2018
Origin:
APS
Abstract Copyright:
2018: authors
DOI:
10.1103/PhysRevC.97.024904
Bibliographic Code:
2018PhRvC..97b4904A

Abstract

A detailed study of multiparticle azimuthal correlations is presented using p p data at √{s }=5.02 and 13 TeV, and p +Pb data at √{sNN}=5.02 TeV, recorded with the ATLAS detector at the CERN Large Hadron Collider. The azimuthal correlations are probed using four-particle cumulants cn{4 } and flow coefficients vn{4 } =(-cn{4 } ) 1 /4 for n =2 and 3, with the goal of extracting long-range multiparticle azimuthal correlation signals and suppressing the short-range correlations. The values of cn{4 } are obtained as a function of the average number of charged particles per event, <" close=">Nch>">Nch</mml:mfenced>, using the recently proposed two-subevent and three-subevent cumulant methods, and compared with results obtained with the standard cumulant method. The standard method is found to be strongly biased by short-range correlations, which originate mostly from jets with a positive contribution to cn{4 } . The three-subevent method, on the other hand, is found to be least sensitive to short-range correlations. The three-subevent method gives a negative c2{4 } , and therefore a well-defined v2{4 } , nearly independent of <mml:mfenced separators=", which implies that the long-range multiparticle azimuthal correlations persist to events with low multiplicity. Furthermore, v2{4 } is found to be smaller than the v2{2 } measured using the two-particle correlation method, as expected for long-range collective behavior. Finally, the measured values of v2{4 } and v2{2 } are used to estimate the number of sources relevant for the initial eccentricity in the collision geometry. The results based on the subevent cumulant technique provide direct evidence, in small collision systems, for a long-range collectivity involving many particles distributed across a broad rapidity interval.

 

Title:
Search for B -L R -parity-violating top squarks in √{s }=13 TeV p p collisions with the ATLAS experiment
Authors:
Aaboud, M.; Aad, G.; Abbott, B.; Abdinov, O.;... Franklin, M.;... Huth, J.;... Morii, M.;... and 2888 coauthors
Publication:
Physical Review D, Volume 97, Issue 3, id.032003 (PhRvD Homepage)
Publication Date:
02/2018
Origin:
APS
Abstract Copyright:
2018: CERN
DOI:
10.1103/PhysRevD.97.032003
Bibliographic Code:
2018PhRvD..97c2003A

Abstract

A search is presented for the direct pair production of the stop, the supersymmetric partner of the top quark, that decays through an R -parity-violating coupling to a final state with two leptons and two jets, at least one of which is identified as a b -jet. The data set corresponds to an integrated luminosity of 36.1 fb-1 of proton-proton collisions at a center-of-mass energy of √{s }=13 TeV , collected in 2015 and 2016 by the ATLAS detector at the LHC. No significant excess is observed over the Standard Model background, and exclusion limits are set on stop pair production at a 95% confidence level. Lower limits on the stop mass are set between 600 GeV and 1.5 TeV for branching ratios above 10% for decays to an electron or muon and a b -quark.

 

Title:
Z Z →ℓ+ℓ-ℓ'+ℓ'- cross-section measurements and search for anomalous triple gauge couplings in 13 TeV p p collisions with the ATLAS detector
Authors:
Aaboud, M.; Aad, G.; Abbott, B.; Abdinov, O.;... Franklin, M.;... Huth, J.;... Morii, M.;... and 2874 coauthors
Publication:
Physical Review D, Volume 97, Issue 3, id.032005 (PhRvD Homepage)
Publication Date:
02/2018
Origin:
APS
Abstract Copyright:
2018: CERN
DOI:
10.1103/PhysRevD.97.032005
Bibliographic Code:
2018PhRvD..97c2005A

Abstract

Measurements of ZZ production in the +'+' channel in proton–proton collisions at 13 TeV center-of-mass energy at the Large Hadron Collider are presented. The data correspond to 36.1fb1 of collisions collected by the ATLAS experiment in 2015 and 2016. Here and stand for electrons or muons. Integrated and differential ZZ+'+' cross sections with Z+ candidate masses in the range of 66 GeV to 116 GeV are measured in a fiducial phase space corresponding to the detector acceptance and corrected for detector effects. The differential cross sections are presented in bins of twenty observables, including several that describe the jet activity. The integrated cross section is also extrapolated to a total phase space and to all standard model decays of Z bosons with mass between 66 GeV and 116 GeV, resulting in a value of 17.3±0.9[±0.6(stat)±0.5(syst)±0.6(lumi)]pb. The measurements are found to be in good agreement with the standard model. A search for neutral triple gauge couplings is performed using the transverse momentum distribution of the leading Z boson candidate. No evidence for such couplings is found and exclusion limits are set on their parameters.

 

Title:
Coherent Bichromatic Force Deflection of Molecules
Authors:
Kozyryev, Ivan; Baum, Louis; Aldridge, Leland; Yu, Phelan; Eyler, Edward E.; Doyle, John M.
Publication:
Physical Review Letters, Volume 120, Issue 6, id.063205 (PhRvL Homepage)
Publication Date:
02/2018
Origin:
APS
Abstract Copyright:
2018: American Physical Society
DOI:
10.1103/PhysRevLett.120.063205
Bibliographic Code:
2018PhRvL.120f3205K

Abstract

We demonstrate the effect of the coherent optical bichromatic force on a molecule, the polar free radical strontium monohydroxide (SrOH). A dual-frequency retroreflected laser beam addressing the X˜2Σ+↔A˜2Π1 /2 electronic transition coherently imparts momentum onto a cryogenic beam of SrOH. This directional photon exchange creates a bichromatic force that transversely deflects the molecules. By adjusting the relative phase between the forward and counterpropagating laser beams we reverse the direction of the applied force. A momentum transfer of 70 ℏk is achieved with minimal loss of molecules to dark states. Modeling of the bichromatic force is performed via direct numerical solution of the time-dependent density matrix and is compared with experimental observations. Our results open the door to further coherent manipulation of molecular motion, including the efficient optical deceleration of diatomic and polyatomic molecules with complex level structures.

 

Title:
Topology, Geometry, and Mechanics of Z -Plasty
Authors:
Matsumoto, Elisabetta A.; Liang, Haiyi; Mahadevan, L.
Publication:
Physical Review Letters, Volume 120, Issue 6, id.068101 (PhRvL Homepage)
Publication Date:
02/2018
Origin:
APS
Abstract Copyright:
2018: American Physical Society
DOI:
10.1103/PhysRevLett.120.068101
Bibliographic Code:
2018PhRvL.120f8101M

Abstract

Reconstructive surgeries often use topological manipulation of tissue to minimize postoperative scarring. The most common version of this, Z -plasty, involves modifying a straight line cut into a Z shape, followed by a rotational transposition of the resulting triangular pedicle flaps, and a final restitching of the wound. This locally reorients the anisotropic stress field and reduces the potential for scarring. We analyze the planar geometry and mechanics of the Z -plasty to quantify the rotation of the overall stress field and the local forces on the restitched cut using theory, simulations, and simple physical Z -plasty experiments with foam sheets that corroborate each other. Our study rationalizes the most typical surgical choice of this angle, and opens the way for a range of surgical decisions by characterizing the stresses along the cut.

 

Title:
Creation of Rydberg Polarons in a Bose Gas
Authors:
Camargo, F.; Schmidt, R.; Whalen, J. D.; Ding, R.; Woehl, G.; Yoshida, S.; Burgdörfer, J.; Dunning, F. B.; Sadeghpour, H. R.; Demler, E.; Killian, T. C.
Publication:
Physical Review Letters, Volume 120, Issue 8, id.083401 (PhRvL Homepage)
Publication Date:
02/2018
Origin:
APS
Abstract Copyright:
2018: American Physical Society
DOI:
10.1103/PhysRevLett.120.083401
Bibliographic Code:
2018PhRvL.120h3401C

Abstract

We report spectroscopic observation of Rydberg polarons in an atomic Bose gas. Polarons are created by excitation of Rydberg atoms as impurities in a strontium Bose-Einstein condensate. They are distinguished from previously studied polarons by macroscopic occupation of bound molecular states that arise from scattering of the weakly bound Rydberg electron from ground-state atoms. The absence of a p -wave resonance in the low-energy electron-atom scattering in Sr introduces a universal behavior in the Rydberg spectral line shape and in scaling of the spectral width (narrowing) with the Rydberg principal quantum number, n . Spectral features are described with a functional determinant approach (FDA) that solves an extended Fröhlich Hamiltonian for a mobile impurity in a Bose gas. Excited states of polyatomic Rydberg molecules (trimers, tetrameters, and pentamers) are experimentally resolved and accurately reproduced with a FDA.

 

Title:
Universal many-body response of heavy impurities coupled to a Fermi sea: a review of recent progress
Authors:
Schmidt, Richard; Knap, Michael; Ivanov, Dmitri A.; You, Jhih-Shih; Cetina, Marko; Demler, Eugene
Publication:
Reports on Progress in Physics, Volume 81, Issue 2, article id. 024401 (2018).
Publication Date:
02/2018
Origin:
IOP
DOI:
10.1088/1361-6633/aa9593
Bibliographic Code:
2018RPPh...81b4401S

Abstract

In this report we discuss the dynamical response of heavy quantum impurities immersed in a Fermi gas at zero and at finite temperature. Studying both the frequency and the time domain allows one to identify interaction regimes that are characterized by distinct many-body dynamics. From this theoretical study a picture emerges in which impurity dynamics is universal on essentially all time scales, and where the high-frequency few-body response is related to the long-time dynamics of the Anderson orthogonality catastrophe by Tan relations. Our theoretical description relies on different and complementary approaches: functional determinants give an exact numerical solution for time- and frequency-resolved responses, bosonization provides accurate analytical expressions at low temperatures, and the theory of Toeplitz determinants allows one to analytically predict response up to high temperatures. Using these approaches we predict the thermal decoherence rate of the fermionic system and prove that within the considered model the fastest rate of long-time decoherence is given by γ=π k_BT/4 . We show that Feshbach resonances in cold atomic systems give access to new interaction regimes where quantum effects can prevail even in the thermal regime of many-body dynamics. The key signature of this phenomenon is a crossover between different exponential decay rates of the real-time Ramsey signal. It is shown that the physics of the orthogonality catastrophe is experimentally observable up to temperatures T/T_F≲ 0.2 where it leaves its fingerprint in a power-law temperature dependence of thermal spectral weight and we review how this phenomenon is related to the physics of heavy ions in liquid {\hspace{0pt}}3 He and the formation of Fermi polarons. The presented results are in excellent agreement with recent experiments on LiK mixtures, and we predict several new phenomena that can be tested using currently available experimental technology.

 

Title:
Observation of three-photon bound states in a quantum nonlinear medium
Authors:
Liang, Qi-Yu; Venkatramani, Aditya V.; Cantu, Sergio H.; Nicholson, Travis L.; Gullans, Michael J.; Gorshkov, Alexey V.; Thompson, Jeff D.; Chin, Cheng; Lukin, Mikhail D.; Vuletić, Vladan
Publication:
Science, Volume 359, Issue 6377, pp. 783-786 (2018). (Sci Homepage)
Publication Date:
02/2018
Category:
PHYSICS
Origin:
SCIENCE
Abstract Copyright:
(c) 2018: Science
DOI:
10.1126/science.aao7293
Bibliographic Code:
2018Sci...359..783L

Abstract

Bound states of massive particles, such as nuclei, atoms, or molecules, constitute the bulk of the visible world around us. By contrast, photons typically only interact weakly. We report the observation of traveling three-photon bound states in a quantum nonlinear medium where the interactions between photons are mediated by atomic Rydberg states. Photon correlation and conditional phase measurements reveal the distinct bunching and phase features associated with three-photon and two-photon bound states. Such photonic trimers and dimers possess shape-preserving wave functions that depend on the constituent photon number. The observed bunching and strongly nonlinear optical phase are described by an effective field theory of Rydberg-induced photon-photon interactions. These observations demonstrate the ability to realize and control strongly interacting quantum many-body states of light.


 go to Most Recent Faculty Publications