Tunneling in a cavity

TL;DR

This paper investigates the phenomenon of coherent destruction of tunneling in a quantum cavity system by analyzing photon statistics, revealing how tunneling dynamics manifest and are affected by quantum interference effects.

Contribution

It introduces a quantum optics perspective to tunneling phenomena, demonstrating how photon statistics reflect tunneling dynamics and interference effects in a cavity coupled to a two-level system.

Findings

Photon statistics reveal tunneling dynamics as a function of interaction time.

Coherent destruction of tunneling causes a slowdown in amplitude modulation at high photon numbers.

Interference between displaced number states explains the phenomenon in the semi-classical limit.

Abstract

The mechanism of coherent destruction of tunneling found by Grossmann et al. [Phys. Rev. Lett. 67, 516 (1991)] is studied from the viewpoint of quantum optics by considering the photon statistics of a single mode cavity field which is strongly coupled to a two-level tunneling system (TS). As a function of the interaction time between TS and cavity the photon statistics displays the tunneling dynamics. In the semi-classical limit of high photon occupation number $n$, coherent destruction of tunneling is exhibited in a slowing down of an amplitude modulation for certain parameter ratios of the field. The phenomenon is explained as arising from interference between displaced number states in phase space which survives the large $n$ limit due to identical $n^{-1/2}$ scaling between orbit width and displacement.