1203.5094 (Chih-Chun Chien et al.)

Interaction-induced conducting-nonconducting transition of ultra-cold
atoms in 1D optical lattices    [PDF]

Chih-Chun Chien, Massimiliano Di Ventra, Michael Zwolak

The study of time-dependent, many-body transport phenomena is increasingly within reach of ultra-cold atom experiments. We show that the introduction of spatially inhomogeneous interactions, e.g., generated by optically-controlled collisions, induce a conducting-to-nonconducting transition in the transport of atoms in 1D optical lattices. Specifically, we simulate the dynamics of interacting fermionic atoms via a micro-canonical transport formalism within both mean-field and other approximations. For weakly repulsive interactions, a quasi steady-state atomic current develops that is similar to the situation occurring for electronic systems subject to an external voltage bias. As the interactions exceed a threshold value, a mean-field conducting-to-nonconducting transition occurs due to energetic constraints. This transition is preceded by the atomic equivalent of negative differential conductivity observed in transport across solid-state structures, but the broad tunability of cold atoms allows for richer non-equilibrium physics.

View original: http://arxiv.org/abs/1203.5094