Correlation and entanglement of two-component Bose-Einstein condensates in a double well

TL;DR

This paper studies a two-component Bose-Einstein condensate in a double well, revealing interaction-induced level crossings, altered quantum oscillations, and quantifying entanglement through entropy and correlation functions.

Contribution

It introduces a detailed analysis of entanglement and level crossings in two-component condensates using the two-mode approximation and numerical methods.

Findings

Avoided level-crossings increase with interactions

Quantum oscillations are modified compared to single-component condensates

Entanglement is characterized by Cauchy-Schwarz violation and Von Neumann entropy

Abstract

We consider a novel system of two-component atomic Bose-Einstein condensate in a double-well potential. Based on the well-known two-mode approximation, we demonstrate that there are obvious avoided level-crossings when both interspecies and intraspecies interactions of two species are increased. The quantum dynamics of the system exhibits revised oscillating behaviors compared with a single component condensate. We also examine the entanglement of two species. Our numerical calculations show the onset of entanglement can be signed as a violation of Cauchy-Schwarz inequality of second-order cross correlation function. Consequently, we use Von Neumann entropy to quantity the degree of entanglement.