Controllable gaussian-qubit interface for extremal quantum state engineering

Phys Rev Lett. 2010 Jun 18;104(24):240501. doi: 10.1103/PhysRevLett.104.240501. Epub 2010 Jun 14.

Abstract

We study state engineering through bilinear interactions between two remote qubits and two-mode gaussian light fields. The attainable two-qubit states span the entire physically allowed region in the entanglement-versus-global-purity plane. Two-mode gaussian states with maximal entanglement at fixed global and marginal entropies produce maximally entangled two-qubit states in the corresponding entropic diagram. We show that a small set of parameters characterizing extremally entangled two-mode gaussian states is sufficient to control the engineering of extremally entangled two-qubit states, which can be realized in realistic matter-light scenarios.