Generation of a superposition of coherent states in a resonant cavity and its nonclassicality and decoherence

We discuss nonclassicality of a superposition of coherent states in terms of sub-Poissonian photon statistics as well as the negativity of the Wigner function. We derive an analytic expression for the Wigner function from which we find that the function has some negative region in phase space. We obtain a compact form of the Wigner function when decoherence occurs and study the effect of decoherence on the state. We demonstrate the behavior of the nonclassicality indicator.PACS Nos.: 42.50.Dv, 03.65.Yz