Entanglement between Bose condensates

Heide Narnhofer

Andrew P. Hines, Ross H. McKenzie, Gerard J Milburn

We investigate the entanglement characteristics of two general bimodal Bose-Einstein condensates---a pair of tunnel-coupled Bose-Einstein condensates and the atom-molecule Bose-Einstein condensate. We argue that the entanglement is only physically meaningful if the system is viewed as a bipartite system, where the subsystems are the two modes. The indistinguishibility of the particles in the condensate means that the atomic constituents are physically inaccessible and, thus, the degree of entanglement between individual particles, unlike the entanglement between the modes, is not experimentally relevant so long as the particles remain in the condensed state. We calculate the entanglement between the two modes for the exact ground state of the two bimodal condensates and consider the dynamics of the entanglement in the tunnel-coupled case.

Soham Sen, Sunandan Gangopadhyay

The effect of noise induced by gravitons on a Bose-Einstein condensate has been explored in Sen and Gangopadhyay [Probing the quantum nature of gravity using a Bose-Einstein condensate, ]. In the previous paper, we investigated the effects of graviton while detecting a gravitational wave using a Bose-Einstein condensate. In this work, we shall explicitly calculate the decoherence due to the noise of gravitons for maximally entangled momentum states of the Bose-Einstein condensate. This decoherence happens due to bremsstrahlung from the Bose-Einstein condensates due to the effect of the noise induced by gravitons. It is observed that the maximally entangled state becomes entangled with the graviton state and it decays over time as a result of this gravitational bremsstrahlung. This new entangled state is termed as a Bose-Einstein supercondensate. Using this property of the Bose-Einstein condensate in a quantum gravity background, we propose an experimental test via the use of atom lasers (generated from the condensate) which would, in principle, help to detect gravitons in future generations of very advanced ultracold temperature experiments.

Jérôme Estève, C. Gross, A. Weller +2 more

Anders Søndberg Sørensen, L.-M. Duan, J. I. Cirac +1 more

Ya‐Feng Liu, Xu‐Bo Zou, Guang‐Can Guo

We propose a scheme to generate maximally entangled states of two distant Bose—Einstein condensates, which are trapped in different potential wells of a one-dimensional optical lattice. We show how such maximally entangled state can be used to test the Bell inequality and realize quantum teleportation of a Bose—Einstein condensate state. The scheme proposed here is based on the interference of Bose—Einstein condensates leaking out from different potential wells of optical lattice. It is briefly pointed out that this scheme can be extended to generate maximally entangled Greenberger—Horne—Zeilinger (GHZ) states of 2m (m > 1) distant Bose—Einstein condensates.