• Theoretical Condensed-Matter Physics
• Theoretical Elementary Particle Physics
• Astrophysics and General Relativity
• Experimental Elementary Particle Physics
• Accelerator Physics
• Experimental Condensed-Matter Physics
• Biological Physics
• Multidisciplinary Research
• Major Research Facilities
• Resources for Researchers

B.Sc., Mathematics/Physics, 1996, University of British Columbia. Ph.D., Physics, 2001, University of Illinois at Urbana Champaign. Postdoctoral fellow, Physics, The Ohio State University 2001-2003. Assistant Professor, Physics, Cornell, 2003-2009. Alfred P. Sloan Fellow, 2005-2007. Associate Professor, Physics, Cornell, 2009-present.

Research Areas
Ultracold atomic gases, quantum optics, strongly correlated matter, and exotic quantum phenomena

Current Research

My current research addresses the evolving theoretical challenges generated by rapid experimental developments in the cooling and manipulating of alkali atoms. This is an ideal system for studying exotic quantum phenomena -- with impact in a range of fields, from condensed matter physics through nuclear physics. Although focused on basic science questions, this research may impact applications in quantum computing, precision measurement, and navigation.

Currently, the most vital theoretical question in this field is what happens when the short-ranged atomic interactions are tuned to resonance, where the system becomes strongly interacting. Properties of the system in this domain are independent of microscopic details, and therefore understanding a resonant atomic gas provides quantitative information about the behavior of other resonant systems -most notably high density nuclear matter. Recent experiments have been studying the crossover from fermionic (BCS) superfluidity to Bose-Einstein condensate of molecules. My group has been studying these systems with a range of tools - from phenomenological models to self-consistent field theories. We have close contact with several experimental groups.

I am also involved in a large number of smaller projects, designed to motivate future experiments in both solid state and atomic systems. As one example, I have been studying the nontrivial topological structures which arise when spinor gases are rotated. There are some beautiful connections between this work and the quantum hall effect seen in two dimensional electron gases.

Graduate Students
Stefan Baur, Kaden Hazzard and Stefan Natu

Spotlight

Yan-Jiun Chen is a graduate student working with Professor Jim Sethna studying non-equilibrium statistical physics, in particular, the scaling properties of crackling noise in magnets.  As a magnet is magnetized, magnetic spins flip in avalanches of all different sizes, this is called the Barkhausen effect (or crackling noise). The properties of these avalanches exhibit self-similarity, and can be studied using powerful theoretical tools in the form of the renormalization group (RG).  This means that studying these avalanches can tell us ...
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