Nonclassicality of noisy quantum states
А. А. Семенов, Dmytro Vasylyev, Bohdan I. Lev · 2005
Abstract. Nonclassicality conditions for an oscillator-like system interacting with a hot thermal bath are considered. Nonclassical properties of quantum states can be conserved up to a certain temperature threshold only. In this case affection of the thermal noise can be compensated via transformation of an observable, which tests the nonclassicality (witness function). Possibilities for experimental implementations based on unbalanced homodyning are discussed. At the same time we demonstrate that the scheme based on balanced homodyning cannot be improved for noisy states with proposed technique and should be applied directly. PACS numbers: 03.65.Yz, 42.50.-p Submitted to: J. Phys. B: At. Mol. Phys. Nonclassicality of noisy quantum states 2