Olga Goulko
(University of Cambridge)
18/06/2010, 16:40
Nonzero temperature and density
Lattice field theory is a useful tool for studying strongly interacting theories in condensed matter physics. A prominent example is the unitary Fermi gas: a two-component system of fermions interacting with divergent scattering length. With Monte Carlo methods this system can be studied from first principles. In presence of an imbalance (unequal number of particles in the two components) a...
Michael G. Endres
(Columbia University)
18/06/2010, 17:00
Nonzero temperature and density
A novel lattice approach is presented for studying systems comprising a large number of interacting nonrelativistic fermions. The construction is ideally suited for numerical study of fermions near unitarity--a strongly coupled regime in which the s-wave scattering length is tuned much larger than all other physical scales. Such systems are experimentally accessible with trapped atoms, and...
Amy N. Nicholson
(Institute for Nuclear Theory, University of Washington)
18/06/2010, 17:20
Nonzero temperature and density
I describe a lattice study of up to N=20 unitary fermions confined to a harmonic trap. Our results show excellent agreement (within 1%) with high precision solutions to the many-body Schrodinger equation for up to N=8. We are also able to make predictions for larger N which were inaccessible by the Hamiltonian approach due to computational limitations. Harmonic traps are used experimentally to...
JONG-WAN LEE
(University of Washington)
18/06/2010, 17:40
Nonzero temperature and density
A fundamental constant in systems of unitary fermions is the so-called Bertsch parameter, the ratio of the ground state energy for spin paired unitary fermions to that for free fermions at the same density. I discuss how we computed this parameter as well as the pairing gap using a recently developed lattice construction for unitary fermions, by measuring correlation functions for up to 38...
