Nonclassicality And Decoherence Of Generalized Photon-modulated Squeezed Thermal State

In quantum optics and quantum information processing, nonclassicality of opticalfields is not only beneficial to comprehend the basic principle of physics, but also hasbeen a topic of great interest. Some traditional quantum state (particle number state,coherent state, squeezed state, etc.) in quantum information processing experiment hasbeen widely applied. Usually, The nonclassicality of quantum states can becharacterized by some specific quantum statistical characteristics, such as the anti-bunching, the sub-Poissonian photon statistics, squeezing in one of the phasequadrature components, the negative distribution of Wigner function and so on. Onaccount of the operator without commutability, it is inconvienient to deal with it.Among them, the partial negativity of the WF is indeed a good indication of thehighly nonclassical character of the state. Therefore it is worth of obtaining the WFfor any states and to measure their negative values.In this paper, we study the nonclassical properties of arbittrary nomber photoncreation-then-annihilation operation (CA) and annihilation-then-creation (AC) to thecoherent states, and give the analytical expression. Because of the noncoummutativityof between annihilation operator and the creation operator, the states generated by ACoperation and CA operation have different nonclassical properties. We study thestatistics characteristics by some nonclassical properties, such as the Mandel Qparameters, the photon number distribution and Wigner function. We mainlyinvestigate the nonclassical properties of GPMSTS and its decoherence in a thermalenvironment according to the negative region of Wigner function. It is found that thenormalization factor of GPMSTS is a Legendre polynomial. Especially, thedecoherence effect is discussed by deriving the time evolution of the Wigner function.