arXiv subjects

Yan-Qing Guo

Publications and source records attributed to Yan-Qing Guo.

5 recordsLinked to original sources

arXiv2017

Enhancing coherence of a state by stochastic strictly incoherent operations

In this paper, we address the issue of enhancing coherence of a state under stochastic strictly incoherent operations. Based on the $l_1$ norm of coherence, we obtain the maximal value of coherence that can be achieved for a state undergoing a stochastic strictly incoherent operation and the maximal probability of obtaining the maximal coherence. Our findings indicate that a pure state can be transformed into a maximally coherent state under a stochastic strictly incoherent operation if and only if all the components of the pure state are nonzero while a mixed state can never be transformed into a maximally coherent state under a stochastic strictly incoherent operation.

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arXiv2015

A proof of the Kochen-Specker theorem can always be converted to a state-independent noncontextuality inequality

Quantum contextuality is one of the fundamental notions in quantum mechanics. Proofs of the Kochen-Specker theorem and noncontextuality inequalities are two means for revealing the contextuality phenomenon in quantum mechanics. It has been found that some proofs of the Kochen-Specker theorem, such as those based on rays, can be converted to a state-independent noncontextuality inequality, but it remains open whether it is true in general, i.e., whether any proof of the Kochen-Specker theorem can always be converted to a noncontextuality inequality. In this paper, we address this issue. We prove that all kinds of proofs of the Kochen-Specker theorem, based on rays or any other observables, can always be converted to state-independent noncontextuality inequalities. Besides, our constructive proof also provides a general approach for deriving a state-independent noncontextuality inequality from a proof of the Kochen-Specker theorem.

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arXiv2005

A position dependent atom-atom entanglement in real-time Cavity QED system

We study a special two-atom entanglement case in assumed Cavity QED experiment in which only one atom effectively exchanges a single photon with a cavity mode. We compute diatom entanglement under position-dependent atomic resonant dipole-dipole interaction (RDDI) for large interatomic separation limit. We show that the RDDI, even which is much smaller than the maximal atomic Rabi frequency, can induce distinct diatom entanglement. The peak entanglement (PE) reaches a maximum when RDDI strength can compare with the Rabi frequency of an atom.

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arXiv2005

Field tuned atom-atom entanglement via diople-dipole interaction

We propose a simple scheme, in which only one atom couples to a cavity field, to entangle two two-level atoms. We connect two atoms with dipole-dipole interaction since one of them can move around the cavity. The results show that the peak entanglment does not depend on dipole-dipole interaction strength but on field density at a certain controlling time. So the field density can act as a switch for maximum entanglement (ME) generation.

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arXiv2005

Local field modulated entanglment among three distant atoms

We extend the scheme for that proposed by S. Mancini and S. Bose (Phys. Rev. A \QTR{bf}{70}, 022307(2004)) to the case of triple-atom. Under mean field approximation, we obtain an effective Hamiltonian of triple-body Ising-model interaction. Furthermore, we stress on discussing the influence of the existence of a third-atom on the two-atom entanglement and testing the modulation effects of locally applied optical fields and fiber on the entanglement properties of our system.

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