Chaos-assisted localization and delocalization of a particle in a driven optical lattice

Abstract

Abstract We investigate quantum chaotic dynamics of a single particle held in a weak amplitude- and tilt-modulated optical lattice with frequency resonance, by using the classical-quantum mixing method. Based on the macroscopic heteroclinic orbit tending to the chaotic “sea” of classical phase space, the quantum chaotic coherent states of the microscopic system are constructed, which show classical-quantum correspondence well. We illustrate the chaotic parameter regions and demonstrate that chaos causes the spread of wave packets and transfers the multiple quantum levels into a single chaotic band. The quantum expected orbit sensitively depends on the initial conditions and system parameters, meaning the famous quantum butterfly effect. Such an effect may lead to the chaotic dynamical localization or delocalization with a certain probability, which can be experimentally observed by matching the driving parameters and initial conditions.