Loading and detecting a three-dimensional Fermi gas in one-dimensional optical superlattice

摘要

We investigate the procedures of loading and detecting three-dimensionalfermionic quantum gases in a one-dimensional optical superlattice potentialsubjected to a trapping potential. Additionally, we consider the relaxationdynamics after a sudden change of the superlattice potential. We numericallysimulate the time-dependent evolution of the continuous system using exactdiagonalization of non-interacting fermions. During the loading procedure weanalyze the occupation of the instantaneous energy levels and compare thesituation in a homogeneous system with the trapped one. Strong differences arefound in particular in the evolution of excitations which we trace back to thedistinct global density distribution. Starting from an imbalanced state in thesuperlattice potential, we consider the relaxation dynamics of fermions after aslow change of the superlattice potential and find a bimodule distribution ofexcitations. To be able to compare with the experimental results we alsosimulate the measurement sequence of the even and odd local density and find astrong dependence of the outcome on the actual ramp procedure. We suggest howthe loading and detecting procedure can be optimized.