Internal Josephson phenomena in a coupled two-component Bose condensate

TL;DR

This paper investigates the internal Josephson phenomena in a two-component Bose-Einstein condensate, revealing various oscillation regimes, including harmonic, anharmonic, and suppressed oscillations, depending on energy detuning.

Contribution

It provides analytical and numerical analysis of coupled condensate dynamics, highlighting new regimes of oscillations influenced by interparticle interactions and energy detuning.

Findings

Identification of regimes of harmonic and anharmonic oscillations

Discovery of a regime where internal oscillations are suppressed

Observation of transitions to Josephson-like effects

Abstract

We discuss the coherent oscillations between two coupled quantum states of a Bose-Einstein condensate in two-dimensional space at zero temperature. In the system we consider, weak interparticle repulsive interactions occur between the particles in state one only, while the state two particles remain non-interacting. Analytical as well as numerical solution of the coupled Gross-Pitaevskii and Schroedinger equations reveals various regimes of oscillational dynamics for the relative quantum phase and population imbalance between the two subsystems of the condensate. We show that, depending on the energy detuning between the two states, the system can exhibit modified harmonic and anharmonic Rabi oscillations or can transit to the regime analogous to internal a.c. Josephson effect. Morover, at a certain value of energy detuning, the internal oscillations are fully suppressed.