Research Associate

CLICK HERE for a list of my papers

My research interests are quantum many-body and few-body systems.

For Fermi gases with large scattering length, I found some general exact relations among energy, momentum distribution, pressure, and the change of energy during the ramp of the scattering length. [References: http://arxiv.org/abs/cond-mat/0505200, http://arxiv.org/abs/cond-mat/0508320]

I studied a Bose Einstein condensate (BEC) of diatomic molecules, emerging in the above Fermi system in the limit of strong attractive interactions. The problem is challenging because one has to put the many-body effects and the nonperturbative 4-body physics into a single framework. Collaborating with Levin, I did this by modifying the BCS-Leggett wave function to incorporate all the few-body correlations, and developing a systematic theory for all the physical observables such as energy, fermion momentum distribution, superfluid order parameter, etc. [References: http://arxiv.org/abs/cond-mat/0506293, http://arxiv.org/abs/cond-mat/0510055]

I recently completed an incomplete calculation by T.T. Wu and others in the 1950's for dilute Bose Einstein condensates. The motivation was to derive observable differences between different BECs with the same scattering length. These differences are called nonuniversal effects. [Reference: http://arxiv.org/abs/0709.2530]

I am now doing similar calculations for dilute Fermi gases, which are another old problem for which one can make new predictions.

My interests extend to new quantum many-body systems. Nishida, Son, and I predicted a Fermi system with both two- and three-body resonant interactions, which is universal and scale invariant, but much more strongly interacting than the familiar unitary Fermi gas. [Reference: http://arxiv.org/abs/0711.1562]

In the longer run I am broadly interested in any strongly interacting many-body system that has interesting physics.

Last modified: 11/13/2007