Steady-state entanglement in a double-well Bose-Einstein condensate through coupling to a superconducting resonator

TL;DR

This paper demonstrates how a double-well Bose-Einstein condensate coupled to a superconducting resonator can achieve steady-state entanglement, which is promising for quantum information processing.

Contribution

It introduces a method to generate steady-state entanglement in a double-well BEC via coupling to a superconducting resonator, highlighting dark-state subspaces in different tunneling regimes.

Findings

Steady-state entanglement is achievable in the weak-tunneling regime.

Dark-state subspaces differ between strong and weak tunneling.

Entanglement can be detected with an entanglement witness.

Abstract

We consider a two-component Bose-Einstein condensate in a double-well potential, where the atoms are magnetically coupled to a single-mode of the microwave field inside a superconducting resonator. We find that the system has the different dark-state subspaces in the strong- and weak-tunneling regimes, respectively. In the limit of weak tunnel coupling, steady-state entanglement between the two spatially separated condensates can be generated by evolving to a mixture of dark states via the dissipation of the photon field. We show that the entanglement can be faithfully indicated by an entanglement witness. Long-lived entangled states are useful for quantum information processing with atom-chip devices.