Finite-dimensional states and entanglement generation for a nonlinear coupler

Abstract

We discuss a system comprising two nonlinear (Kerr-like) oscillators coupled mutually by a nonlinear interaction. The system is excited by an external coherent field that is resonant to the frequency of one of the oscillators. We show that the coupler evolution can be closed within a finite set of $n$-photon states, analogously as in the \textit{nonlinear quantum scissors} model. Moreover, for this type of evolution our system can be treated as a \textit{Bell-like states} generator. Thanks to the nonlinear nature of both: oscillators and their internal coupling, these states can be generated even if the system exhibits its energy dissipating nature, contrary to systems with linear couplings.Comment: Accepted for publication in Physical Review