De-Gaussification by inconclusive photon subtraction

Abstract

We address conditional de-Gaussification of continuous variable states by inconclusive photon subtraction (IPS) and review in details its application to bipartite twin-beam state of radiation. The IPS map in the Fock basis has been derived, as well as its counterpart in the phase-space. Teleportation assisted by IPS states is analyzed and the corresponding fidelity evaluated as a function of the involved parameters. Nonlocality of IPS states is investigated by means of different tests including displaced parity, homodyne detection, pseudospin, and displaced on/off photodetection. Dissipation and thermal noise are taken into account, as well as non unit quantum efficiency in the detection stage. We show that the IPS process, for a suitable choice of the involved parameters, improves teleportation fidelity and enhances nonlocal properties.