Semiclassical analysis of ultracold fermions in driven lattices: generation of intrinsic photocurrents.
By: Alexander Itin
From: University of Hamburg
At: Instituto de Investigação Interdisciplinar, B3-01
[2012-12-11]
I present theoretical study of recent experimental simulations of photoconductivity using fermionic atoms in optical lattices [J. Heinze et. al.,arXiv:1208.4020v2].
Amplitude modulation of an optical lattice was used to create an analog to a persistent alternating photocurrent in an ultracold gas of fermionic atoms. The dynamics is induced and sustained by an external harmonic confinement. While particle excitations exhibit long-lived oscillations with a frequency depending on their initial quasimomentum, a strikingly different behavior is observed for holes.
They quickly disappear followed by subsequent periodic revivals. Both observations are explained and theoretically described by mapping the system onto a classical nonlinear Hamiltonian using Truncated Wigner Approximation. In case time is enough, I will also discuss several other systems where ensembles of classical trajectories allow to quantitatively describe quantum dynamics, e.g. quantum phase transitions in Dicke models.