Quantum dynamics in the bosonic Josephson junction

TL;DR

This paper investigates the quantum dynamics of a bosonic Josephson junction using semiclassical methods, revealing how initial conditions influence phase diffusion, coherence buildup, and the transition to classical behavior.

Contribution

It introduces a semiclassical approach to analyze how initial states affect coherence and classicality in bosonic Josephson junctions, highlighting differences based on initial conditions.

Findings

Phase diffusion depends on initial relative phase.

Universal coherence buildup for incoherent initial states.

Distinct convergence behaviors to classicality for different initial preparations.

Abstract

We employ a semiclassical picture to study dynamics in a bosonic Josephson junction with various initial conditions. Phase-diffusion of coherent preparations in the Josephson regime is shown to depend on the initial relative phase between the two condensates. For initially incoherent condensates, we find a universal value for the buildup of coherence in the Josephson regime. In addition, we contrast two seemingly similar on-separatrix coherent preparations, finding striking differences in their convergence to classicality as the number of particles increases.