Harvard University Department of Physics

The Morris Loeb Lecture in Physics: Marc Mézard

Colloquium (Apr 28): "The spin glass cornucopia"
Lecture I (Apr 29): "Phase transitions in hard computer science problems"
Lecture II (Apr 30): "Occam’s razor in massive data acquisition: a statistical physics approach"

Topological Excitations and the Dynamic Structure Factor of Spin Liquids on the Kagome Lattice

Recent neutron scattering experiments on the spin-1/2 kagome lattice antiferromagnet ZnCu3(OH)6Cl2 (Herbertsmithite) provide the first evidence of fractionalized excitations in a quantum spin liquid state in two spatial dimensions...

Angular Fluctuations of a Multi-Component Order Describe the Pseudogap Regime of the Cuprate Superconductors

The hole-doped cuprate high-temperature superconductors enter the pseudogap regime as their superconducting critical temperature, Tc, falls with decreasing hole density...

Fall 2013 Certificate of Distinction in Teaching Awards

Graduate students Prahar Mitra, Elliot Schneider, Elizabeth Petrik, Nicholas Schade, Alexandru Lupsasca, Chi-Ming Chang, and Timothy Koby have been awarded the Harvard University Certificate of Distinction in Teaching for the Fall 2013 term by the Derek Bok Center.

First Direct Evidence of Cosmic Inflation

The BICEP2 Collaboration, led by Professor John Kovac, has announced the discovery of first direct evidence of cosmic inflation, the expansion of space first proposed in 1981 by Alan Guth of MIT. Watch the VIDEO.

EPiQS Funding to Boost Quantum Materials Theory Research

Harvard has been chosen one of the six receipients of Gordon and Betty Mooore Foundation's Emergent Phenomena in Quantum Systems (EPiQS) grants...

Dark Matter as a Trigger for Periodic Comet Impacts

Professors Lisa Randall and Matthew Reece suggest that a smooth disc of dark matter passing through the Galaxy approximately every 35 million years might be the underlying cause of the cycles of increased meteorite activity on Earth, such as the one that led to the extinction of the dinosaurs...

Prof. Mazur Inducted into the Royal Holland Society of Sciences and Humanities

The Society... was established in 1752 by seven distinguished burghers of the city of Haarlem, in the then Republic of the United Provinces of the Netherlands, in order "to promote science" (in the broadest sense, including the "arts")

UPCOMING EVENTS

Tomorrow

Engineering and Physical Biology Annual Symposium
- On Saturday, April 26, the annual Engineering and Physical Biology (EPB) Symposium will be held in Room B103 of the Northwest Building, 52 Oxford St. Speakers from constituent fields -Physics, Engineering, Chemistry and Molecular Biology - will present significant recent findings ranging from the physics of protein conformation to DNA knotting.
  
  As in the past, the EPB Symposium day has been organized to bring together students and faculty from three Harvard areas (MCB, Physics and SEAS) with outstanding visiting scholars. (For a review of last year’s Symposium, see https://www.mcb.harvard.edu/mcb/news/news-detail/3684/symposium-features-physical-biology-research/) EPB is now in its eighth year as a PhD track for students wishing to “probe living systems through the lens of physics and engineering.”
  
  The day will be divided into two parts. The morning (until 12:30 pm) will be a public symposium featuring four visiting faculty. (See poster to your right) The public is welcome to attend, and the talks should be of wide interest to the Harvard science community.
  
  The afternoon will feature graduate student presentations and discussions in a more intimate setting that should promote the cross-fertilization of disciplines that EPB encapsulates. (These sessions will not be open to the general public.)
  
  Work at physics and engineering interface is rapidly becoming an established part of the life sciences. EPB particularly welcomes members of the MCB community to engage with these speakers working on the frontiers of physical biology.
  
  Morning Schedule - Public Event:
  
  9:00 - 9:45:
  Marco Foiani Prof. of Molecular Biology, Dept. of Biosci., University
  of Milan and IFOM-IEO “Mechanosensing at the nuclear envelope: an ATR-mediated
  response to control cell plasticity”
  
  9:45 – 10:30
  Kerry Bloom Dept. of Biology, Univ. of North Carolina, Chapel Hill
  "The landscape of forces in mitosis"
  
  10:30 – 11:00 Coffee Break
  
  11:00 – 11:45
  Jonathon Howard Eugene Higgins Prof. of Molecular Physics & Biochem., Yale University
  and Max Planck Inst., Dresden "Ciliary and flagellar motility: From single molecules to
  collective motion"
  
  11:45 – 12:30
  Olaf Sparre Andersen Prof. of Physiol. & Biophys., Weill Cornell Medical College
  "Interactions of drugs and other amphiphiles with membranes: Implications for membrane
  protein function and drug development"
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Monday, April 28th

Physics Colloquium Tea
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"The Spin Glass Cornucopia," Marc Mézard, Ecole Normale Supérieure, Paris
- For more than 30 years, the spin glass puzzle has stimulated a large activity in statistical physics, and led to several breakthroughs. While the puzzle of spin glass materials is still not fully solved, their theoretical analysis has created a very rich conceptual framework, as well as powerful techniques, to study emergent properties of strongly disordered and interacting systems. These have been successfully applied to a broad spectrum of
  other disciplines, from finance to computer science and information theory, where slow -glassy- dynamics and phase transitions play a key role. The talk will survey this spin glass saga, focusing on its developments outside of physics.
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Tuesday, April 29th

“Phase transitions in hard computer science problems,” Marc Mézard, Ecole Normale Supérieure, Paris
- A new field of research is rapidly expanding at the crossroad between statistical physics, information theory and combinatorial optimization. It deals with problems which are very important in each of these fields, like spin glasses, error correction, or satisfiability. In recent years, it has been realized that physical phenomena, familiar from glass phenomenology, occur in large classes of algorithms that have been developed to study some of the hardest computer science problems. Realizing that extreme slowdown and glassy phase transitions occur in computer programs is interesting both theoretically, as it opens new perspectives to the study of algorithmic complexity, as well as practically : it allows to develop new kind of efficient algorithms, inspired from insights obtained through the “replica method” and the “cavity method’’. This talk will survey these recent developments, focusing on the conceptual leap induced by the use of spin glass theory in hard constraint satisfaction problems.
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Anže Slosar (Brookhaven) "BICEP2 and the future of cosmological observations"
- I will give an overview of the recent BICEP2 detection of the primordial gravitational waves from an experimentalist's perspective, discussing reasons to believe the result and reasons to worry about. I will next discuss how this result, if confirmed, affects our priors about the inflation and planning of the future experiments. I will discuss which observables we should try to measure, how to do these measurements and what are the leading systematics.
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Wednesday, April 30th

“Occam’s razor in massive data acquisition: a statistical physics approach," Marc Mézard, Ecole Normale Supérieure, Paris
- Science is facing several challenges related to data explosion. How to acquire a large amount of information in short time? How to extract significant data? In recent years, studies in compressed sensing have triggered very interesting developments on these issues. Compressed sensing consists in sampling a sparse signal at low rate, and later using computational power for its exact reconstruction, so that only the necessary information is measured. Currently used reconstruction techniques are, however, limited to acquisition rates larger than the true density of the signal. We shall describe new procedures, based on a statistical physics analysis, which is able to reconstruct exactly the signal with a number of measurements that approaches the theoretical limit for large systems.
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LPPC Seminar: Mike Kordosky
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Alain Karma; Northeastern University
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Thursday, May 1st

CMP Seminar: Naomichi Hatano
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Jim Halverson (KITP)
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