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

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 different dark-state subspaces in the strong- and weak-tunneling regimes. 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. © 2011 American Physical Society.