Superposition of Photon Subtraction and Photon Addition Excited Squeezed Thermal State and its Wigner Function

We introduce the superposition of photon subtraction and photon addition excited squeezed thermal state (SPSAST) that is generated by operation of superposition of photon subtraction and photon addition on squeezed thermal state. By the technique of integration within an ordered product of operators, we derive its normalization constant and the analytical expression of its Wigner function. The influences of the squeezing parameter and superposition coefficient of operators on its non-classical properties are discussed. Numerical results show that its non-classical properties are firstly strengthened with the increasing of the squeezing parameter in the beginning. However, when the squeezing parameter is larger than a certain value, its non-classical properties are weakened as the squeezing parameter continues to grow. The influence of the superposition coefficient of operators on its non-classical properties is complex. On the other hand, its non-classical properties are weakened with the increasing of the average photon number in the thermal state.