An N-mode squeezed vacuum state in Fock space as an entangled state

Abstract

Using the technique of integration within the ordered product (IWOP) of operators, we show that the operator U = exp [ir(∑n−1i=1QiPi+1 + QnP1)] is an N-mode squeezing operator for the N-mode quadratures exhibiting the standard squeezing. The corresponding squeezed vacuum state in N-mode Fock space is derived, and the entanglement involved in such a state is also explained. We present an optical network for producing the N-mode squeezed state.