Phase Coherence in a Driven Double-Well System

TL;DR

This paper investigates how quantum fluctuations lead to phase coherence in a driven double-well molecular system, revealing different steady-state phase distributions based on interaction and tunnelling ratios.

Contribution

It introduces a detailed analysis of phase coherence development in a quantum tunnelling system influenced by molecular interactions and identifies distinct steady-state regimes.

Findings

Three different steady-state phase distributions identified

Crossover from phase-coherent to phase-incoherent regimes analyzed

Quantum fluctuations initiate phase coherence from vacuum state

Abstract

We analyze the dynamics of the molecular field incoherently pumped by the photoassociation of fermionic atoms and coupled by quantum tunnelling in a double-well potential. The relative phase distribution of the molecular modes in each well and their phase coherence are shown to build up owing to quantum mechanical fluctuations starting from the vacuum state. We identify three qualitatively different steady-state phase distributions, depending on the ratio of the molecule-molecule interaction strength to interwell tunnelling, and examine the crossover from a phase-coherent regime to a phase-incoherent regime as this ratio increases.