Analytical Pendulum Model for a Bosonic Josephson Junction

TL;DR

This paper develops an analytical pendulum-based model for tunneling dynamics in bosonic Josephson junctions, providing insights aligned with experiments and extending classical analogies to include asymmetries and dissipation.

Contribution

It introduces a classical pendulum analogy for the bosonic Josephson junction dynamics, incorporating asymmetry and dissipation, and aligns with mean-field and experimental observations.

Findings

Model accurately describes tunneling dynamics.

Inclusion of asymmetry and dissipation improves experimental agreement.

Provides experimentally measurable parameters for system analysis.

Abstract

We present an analytical description of the tunneling dynamics between two coupled Bose-Einstein condensates in the Josephson regime. The model relies on the classical analogy with a rigid pendulum and focuses on two dynamical modes of this system: Josephson oscillations and Macroscopic Quantum Self-Trapping. The analogy is extended to include an energy difference between the two superfluids caused by an asymmetry in the trapping potential. The model is compatible with the mean-field predictions of the two-mode Bose-Hubbard model. It gives new insights on the mean-field model by involving experimentally measurable parameters with reduced correlations. For agreement with recent experimental observations, we establish heuristic formulas including a dissipation. We conclude with a convincing application of the model to several sets of experimental results.