Quasiprobability distributions in open quantum systems: spin-qubit systems

Abstract We study nonclassical features in a number of spin-qubit systems including single, two and three qubit states, as well as an N qubit Dicke model and a spin-1 system, of importance in the fields of quantum optics and information. This is done by analyzing the behavior of the well known Wigner, P , and Q quasiprobability distributions on them. We also discuss the not so well known F function and specify its relation to the Wigner function. Here we provide a comprehensive analysis of quasiprobability distributions for spin-qubit systems under general open system effects, including both pure dephasing as well as dissipation. This makes it relevant from the perspective of experimental implementation.