Nonclassical Properties of Thermal Quantum States

Fataneh Zehtabzadeh, Mohammad Javad Faghihi, Hamidreza Baghshahi

Xiaoyan Zhang, Zhenbao Feng, Ji‐Suo Wang +2 more

We theoretically introduce a new kind of non-Gaussian state, namely, the mixture of multiphoton added thermal states, achieved through multiphoton measurements at one output port of the beam splitter (termed multiphoton catalysis) for thermal state input. We discuss the success probabilities of detection (the normalization factors). Furthermore, we investigate their nonclassical properties based on the nonclassical depth, photon number distribution, and photocount distribution. It is shown that the multiphoton catalysis presents a better nonclassical performance by controlling the thermal parameter, catalyzed photon number and the transmissivity of the beam splitter. In addition, the nonclassicality is further examined through the partial negativity of the Wigner function, which reveals that multiphoton catalysis operation can prepare highly nonclassical quantum states. These results indicate that the preparation of a non-Gaussian states may have potential applications in the realms of quantum information processing and quantum metrology.

P.E.R. Weber, Vinícius N. A. Lula-Rocha, J.C.C. Pereira +5 more

E. Rafiepoor, M. R. Bazrafkan, Saeed Batebi

A A Semenov, D Yu Vasylyev, B I Lev

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 the proposed technique and should be applied directly.

Lars M. Johansen