Qin Guo — Page 2 | Searcharxiv

arXiv2010

Entanglement and nonlocality of one- and two-mode combination squeezed state

We investigate the entanglement and nonlocality properties of one- and two-mode combination squeezed vacuum state (OTCSS, with two-parameter lamda and gamma) by analyzing the logarithmic negativity and the Bell's inequality. It is found that this state exhibits larger entanglement than that of the usual two-mode squeezed vacuum state (TSVS), and that in a certain regime of lamda, the violation of Bell's inequality becomes more obvious, which indicates that the nonlocality of OTCSS can be stronger than that of TSVS. As an application of OTCSS, the quantum teleportaion is examined, which shows that there is a region spanned by lamda and gamma in which the fidelity of OTCSS channel is larger than that of TSVS.

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arXiv2006

Husimi operator and Husimi function for describing electron's probability distribution in uniform magnetic field derived by virtue of the entangled state representation

For the first time we introduce the Husimi operator Delta_h(gamma,varepsilon;kappa) for studying Husimi distribution in phase space(gamma,varepsilon) for electron's states in uniform magnetic field, where kappa is the Gaussian spatial width parameter. Using the Wigner operator in the entangled state |lambda> representation [Hong-Yi Fan, Phys. Lett. A 301 (2002)153; A 126 (1987) 145) we find that Delta_h(gamma,varepsilon;kappa) is just a pure squeezed coherent state density operator |gamma,varepsilon>_kappa kappa<gamma,varepsilon|, which brings convenience for studying and calculating the Husimi distribution. We in many ways demonstrate that the Husimi distributions are Gaussian-broadened version of the Wigner distributions. Throughout our calculation we have fully employed the technique of integration within an ordered product of operators.

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