Robust generation of entanglement in Bose-Einstein condensates by collective atomic recoil

Abstract

We address the dynamics induced by collective atomic recoil in a Bose-Einstein condensate in presence of radiation losses and atomic decoherence. In particular, we focus on the linear regime of the lasing mechanism, and analyze the effects of losses and decoherence on the generation of entanglement. The dynamics is that of three bosons, two atomic modes interacting with a singlemode radiation field, coupled with a bath of oscillators. The resulting three-mode dissipative Master equation is solved analytically in terms of the Wigner function. We examine in details the two complementary limits of high-Q cavity and bad-cavity, the latter corresponding to the so-called superradiant regime, both in the quasi-classical and quantum regimes. We found that three-mode entanglement as well as two-mode atom-atom and atom-radiation entanglement is generally robust against losses and decoherence,thus making the present system a good candidate for the experimental observation of entanglement in condensate systems. In particular, steady-state entanglement may be obtained both between atoms with opposite momenta and between atoms and photons.

Quantum optics in the phase space

“…This kind of Hamiltonian can be experimentally realized by means of parametric processes in quantum optical [20,21], optomechanical [22,23], micromechanical [24] and cold gases [25,26,27,28,29,30] systems. Though the actual realization of these transformations necessarily involves parametric interactions in nonlinear media, their quantum optical implementation is often referred to as quantum information processing with linear optics, according to the linearity of mode evolution.…”

The Balance of Quantum Correlations for a Class of Feasible Tripartite Continuous Variable States

“…The three-mode entanglement generated by H may be indeed exploited to realize optimal cloning at distance of coherent states 19 . Analogue interaction schemes may be realized in condensate systems 45,46 . The Hamiltonian in Eq.…”

Rayleigh superradiance and dynamic Bragg gratings in an end-pumped Bose-Einstein condensate

“…Equations (2) and (3) show terms equivalent to the coupling terms in Eqn. (1). Specifically, the growth of e − occurs with the corresponding growth of recoiling atoms ψ m+2 and the decrease of e + photons and ψ m atoms.…”

“…Nt,37.10.Vz,42.50.Gy With its extremely high optical depth and unique coherence properties, a Bose Einstein condensate provides an ideal object on which to study collective light scattering with the goal of generating and probing light-atom correlations. Superradiant light scattering (SLS) from ultra-cold atomic ensembles has been recognized as a method to generate entangled atoms and photons due to the fact that the interaction Hamiltonian has the generic form of a parametric amplifier H ∝â †b † , where correlations based on momentum conservation arise in the case of Rayleigh scattering [1], and angular momentum in the case of Raman processes [2]. Entanglement in the ultra-low gain regime of such an interaction, when far less than one atom-photon excitation pair is generated on average, forms the basis for a quantum repeater [3] and has been studied extensively [4].…”