Quasi-spin Model for Macroscopic Quantum Tunnelling between Two Coupled Bose-Einstein Condensates

TL;DR

This paper models macroscopic quantum tunneling between two coupled Bose-Einstein condensates using a quasi-spin approach, calculating tunneling exponents and crossover temperatures to aid quantum control and computation.

Contribution

It introduces a quasi-spin model for coupled BECs and derives tunneling properties, providing new insights into quantum control in these systems.

Findings

Tunneling exponent dependence on system parameters

Estimated crossover temperature from thermal to quantum regime

Mapped BEC tunneling onto uniaxial spin tunneling

Abstract

The macroscopic quantum tunneling between two coupled Bose-Einstein condensates (BEC) (radio-frequency coupled two-component BECs or two BECs confined in a double-well potential) is mapped onto the tunneling of an uniaxial spin with an applied magnetic field. The tunneling exponent is calculated with an imaginary-time path-integral method. In the limit of low barrier, the dependence of tunneling exponent on the system parameters is obtained, and the crossover temperature from thermal regime to quantum regime is estimated. The detailed information about the tunnelling will give help to control population conversion between coupled BECs and realize quantum computation with coupled BECs.