TY - JOUR
T1 - Heavy fermions in an optical lattice
JF - Physical Review A
Y1 - 2010
A1 - Michael Foss-Feig
A1 - Michael Hermele
A1 - Victor Gurarie
A1 - Ana Maria Rey
AB - We employ a mean-field theory to study ground-state properties and transport of a two-dimensional gas of ultracold alklaline-earth metal atoms governed by the Kondo Lattice Hamiltonian plus a parabolic confining potential. In a homogenous system this mean-field theory is believed to give a qualitatively correct description of heavy fermion metals and Kondo insulators: it reproduces the Kondo-like scaling of the quasiparticle mass in the former, and the same scaling of the excitation gap in the latter. In order to understand ground-state properties in a trap we extend this mean-field theory via local-density approximation. We find that the Kondo insulator gap manifests as a shell structure in the trapped density profile. In addition, a strong signature of the large Fermi surface expected for heavy fermion systems survives the confinement, and could be probed in time-of-flight experiments. From a full self-consistent diagonalization of the mean-field theory we are able to study dynamics in the trap. We find that the mass enhancement of quasiparticle excitations in the heavy Fermi liquid phase manifests as slowing of the dipole oscillations that result from a sudden displacement of the trap center.
VL - 82
UR - http://arxiv.org/abs/1007.5083v1
CP - 5
J1 - Phys. Rev. A
U5 - 10.1103/PhysRevA.82.053624
ER -
TY - JOUR
T1 - Probing the Kondo Lattice Model with Alkaline Earth Atoms
JF - Physical Review A
Y1 - 2010
A1 - Michael Foss-Feig
A1 - Michael Hermele
A1 - Ana Maria Rey
AB - We study transport properties of alkaline-earth atoms governed by the Kondo Lattice Hamiltonian plus a harmonic confining potential, and suggest simple dynamical probes of several different regimes of the phase diagram that can be implemented with current experimental techniques. In particular, we show how Kondo physics at strong coupling, low density, and in the heavy fermion phase is manifest in the dipole oscillations of the conduction band upon displacement of the trap center.
VL - 81
UR - http://arxiv.org/abs/0912.4762v1
CP - 5
J1 - Phys. Rev. A
U5 - 10.1103/PhysRevA.81.051603
ER -