Designs of interactions between discrete- and continuous-variable states for generation of hybrid entanglement

Abstract

We develop theory of realizing different types of hybrid entanglement between discrete-variable (single photon) and continuous-variable states (coherent states). The key mechanism for generating such hybrid entangled states is thanks to superposing microscopic discrete-variable state with macroscopic continuous-variable Schrodinger cat state on highly transmissive beam splitter followed by measurement strategies in such a way that all the information about the amplitude of the continuous-variable state is erased. Conditions for obtaining the balanced hybrid entangled states are established and their degree of entanglement is evaluated.