Coherent control via interplay between driving field and two-body interaction in a double well

TL;DR

This paper analytically explores how external driving fields and interatomic interactions influence quantum tunneling of two bosons in a double well, revealing mechanisms for controlling tunneling via resonance effects and coherent destruction of tunneling.

Contribution

It provides an analytical solution using Floquet states to understand and control quantum tunneling in a driven double well system, highlighting resonance effects and tunneling suppression mechanisms.

Findings

Photon resonance shifts Floquet level-crossing points.

Non-resonant interaction causes avoided level crossings.

Resonant interactions enhance tunneling, non-resonant decrease it.

Abstract

We investigate interplay between external field and interatomic interaction and its applications to coherent control of quantum tunneling for two repulsive bosons confined in a high-frequency driven double well. A full solution of the system is generated analytically as a coherent non-Floquet state by using the Floquet states as a set of complete bases. It is demonstrated that the photon resonance of interaction leads to translation of the Floquet level-crossing points, and the non-resonant interaction causes avoided crossing of partial levels. In the non-Floquet states, the bosons beyond the crossing points slowly vary their populations, and the resonant (non-resonant) interactions enhance (decrease) the tunneling rate of the paired particles. Three different kinds of the coherent destructions of tunneling (CDT) at the crossing, avoided-crossing and uncrossing points, and the corresponding stationary-like states, are illustrated. The analytical results are numerically confirmed and perfect agreements are found. Based on the results, an useful scheme of quantum tunneling switch between stationary-like states is presented.