Quantum tunneling in the driven Lipkin N-body problem

Abstract

Quantum tunneling is investigated in the quantum and semiclassical limits using a periodically driven Lipkin N-body model. The time-dependent driving changes the tunneling rate by orders of magnitude as compared to the unperturbed system, leading to its enhancement in a somewhat similar way as found recently in the simple one-dimensional anharmonic-oscillator model for one particle. Oscillatory and coherent tunneling of the N-particle wave-function between two degenerate Hartree-Fock minima is found when the initial wave-function is localized in one doublet of quasienergy states of different parity. The coherent suppression of tunneling is also found for specific parameters of the driving force.