Energy band structure and intrinsic coherent properties in two weakly linked Bose Einstein Condensates

TL;DR

This paper investigates the energy band structure and coherence properties of two weakly linked Bose-Einstein condensates, revealing how energy splitting influences phase coherence and dissipation in Bose Josephson junctions.

Contribution

The study calculates energy band structures using the instanton method and analyzes intrinsic coherence in Bose Josephson junctions across different regimes of energy ratios.

Findings

Small energy splitting when E_C/E_J << 1 indicates phase coherence.

Large energy splitting when E_C/E_J >> 1 leads to phase dissipation.

Optimal coherence occurs near E_C/E_J ≈ 1.

Abstract

The energy band structure and energy splitting due to quantum tunneling in two weakly linked Bose-Einstein condensates were calculated by using the instanton method. The intrinsic coherent properties of Bose Josephson junction were investigated in terms of energy splitting. For $E_{C}/E_{J}\ll 1$, the energy splitting is small and the system is globally phase coherent. In the opposite limit, $E_{C}/E_{J}\gg 1$, the energy splitting is large and the system becomes a phase dissipation. Our reslults suggest that one should investigate the coherence phenomna of BJJ in proper condition such as $E_{C}/E_{J}\sim 1$.