Quantum Coherent Atomic Tunneling between Two Trapped Bose-Einstein Condensates

TL;DR

This paper investigates the quantum tunneling dynamics between two Bose-Einstein condensates in a double-well trap, revealing a novel self-trapping effect due to nonlinear interactions.

Contribution

It introduces a theoretical model describing coherent tunneling and predicts a new macroscopic quantum self-trapping phenomenon in BECs.

Findings

Identification of a self-maintained population imbalance

Prediction of a macroscopic quantum self-trapping effect

Extension of Josephson dynamics to nonlinear BEC systems

Abstract

We study the coherent atomic tunneling between two zero-temperature Bose-Einstein condensates (BEC) confined in a double-well magnetic trap. Two Gross-Pitaevskii equations for the self-interacting BEC amplitudes, coupled by a transfer matrix element, describe the dynamics in terms of the inter-well phase-difference and population imbalance. In addition to the anharmonic generalization of the familiar $ac$ Josephson effect and plasma oscillations occurring in superconductor junctions, the non-linear BEC tunneling dynamics sustains a self-maintained population imbalance: a novel "macroscopic quantum self-trapping effect".