States with holes in Fock space in a mesoscopic Josephson junction

Recently a state with holes in Fock space corresponding to a nonclassical s tate has been studied. In this paper we study the interaction between a mes oscopic Josephson junction and nonclassical microwave, treating both quantu m mechanically. We introduce the creation and the annihilation operators fo r the junction. Within the external field approximation, we show that the s tate of the junction can evolve into a superposition of two coherent states , which can become a state with holes in Fock space for some specific param eters.