Osmotic-pressure-controlled concentration of colloidal particles in thin-shelled capsules

January 31, 2014

(a) Schematic illustration of isotropic shrinkage of a liquid capsule under hypertonic condition; the capsule shrinks until the osmotic pressure difference becomes negligible. (b) A series of optical microscope images showing isotropic shrinkage of liquid capsules consisting of 10 wt.% aqueous core of PVA with 100 mOsml−1 and ETPTA membrane, where the capsules are dispersed in aqueous solution with 460 mOsml−1. Scale bar, 100 μm. (Figures reprinted by permission from Macmillan Publishers Ltd: Nature ©2014.)


Prof. Matthew Schwartz published a new book

January 14, 2014

From the Publisher's Summary:

Providing a comprehensive introduction to quantum field theory, this textbook covers the development of particle physics from its foundations to the discovery of the Higgs boson. Its combination of clear physical explanations, with direct connections to experimental data, and mathematical rigor make the subject accessible to students with a wide variety of backgrounds and interests. Assuming only an undergraduate-level understanding of quantum mechanics, the book steadily develops the Standard Model and state-of-the art calculation techniques...


Measuring Electron's Electric Dipole Moment

January 10, 2014

A collimated pulse of ThO molecules enters a magnetically shielded region (not to scale). An aligned spin state (smallest red arrows), prepared via optical pumping, precesses in parallel electric and magnetic fields. The final spin alignment is read out by a laser with rapidly alternating linear polarizations, X and Y, with the resulting fluorescence collected and detected with photomultiplier tubes (PMTs). [from The ACME Collaboration: J. Baron, W.C. Campbell, D. DeMille, J.M. Doyle1, G.


Origins of Slowly Fading Super-Luminous Supernovae

November 12, 2013

Super-luminous supernovae that radiate more than 1044 ergs per second at their peak luminosity have recently been discovered in faint galaxies at redshifts of 0.1–4. Some evolve slowly, resembling models of 'pair-instability' supernovae. Such models involve stars with original masses 140–260 times that of the Sun that now have carbon–oxygen cores of 65–130 solar masses. In these stars, the photons that prevent gravitational collapse are converted to electron–positron pairs, causing rapid contraction and thermonuclear explosions. Many solar masses of 56Ni are synthesized; this isotope decays to 56Fe via 56Co, powering bright light curves.


Unconventional Sequence of Fractional Quantum Hall States in Suspended Graphene

October 19, 2013

Graphene provides a rich platform to study many-body effects, owing to its massless chiral charge carriers and the fourfold degeneracy arising from their spin and valley degrees of freedom. Graduate student Ben Feldman, Prof. Amir Yacoby, and colleagues from Max-Planck-Institut in Stuttgart used a scanning single-electron transistor to measure the local electronic compressibility of suspended graphene, and observed an unusual pattern of incompressible fractional quantum Hall states that follows the standard composite fermion sequence between filling factors ν = 0 and 1 but involves only even-numerator fractions between ν = 1 and 2.