We present a scheme to realize a special quantum cloning machine via input-output cavities.The cloning machine can copy information from one atom to another distant atom.Choosing different parameters,the method can pe...We present a scheme to realize a special quantum cloning machine via input-output cavities.The cloning machine can copy information from one atom to another distant atom.Choosing different parameters,the method can perform optimal symmetric(asymmetric)universal quantum cloning and optimal symmetric(asymmetric)phase-covariant cloning.Compared to previous schemes,our scheme is more insensitive to actual environmental noise and can get higher fidelity in a current cavity quantum electrodynamics system with an entangled state acting as a quantum channel than a single-photon pulse.展开更多
The thermal entanglement in the spin-S Heisenberg XYZ model is studied in detail by using the entanglement measure of negativity. The effects of spin on the thermal entanglement, the threshold temperature, the critica...The thermal entanglement in the spin-S Heisenberg XYZ model is studied in detail by using the entanglement measure of negativity. The effects of spin on the thermal entanglement, the threshold temperature, the critical uniform external magnetic field, the nonuniform external magnetic field and the＇, entanglement extremum are discussed, respectively. It is shown that with increasing spin, the entanglement will increase, and then decrease slowly. In addition, we find that entanglement will approach a constant Nc with the increase of DM interaction, the constant increases with the increase of spin, and both the threshold temperature Tc and critical uniform external magnetic field Bc will increase with the increasing spin. Thus high-spin system can inhibit the influence of the external environment better.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 11204061,61073048,11104057the Anhui Provincial Natural Science Foundation under Grant No 11040606M16+2 种基金the China Postdoctoral Science Foundation under Grant No 20110490825the Major Program of the Education Department of Anhui Province under Grant No KJ2010ZD08the Key Program of the Education Department of Anhui Province under Grant Nos KJ2012A244,KJ2011A243,KJ2012A020.
文摘We present a scheme to realize a special quantum cloning machine via input-output cavities.The cloning machine can copy information from one atom to another distant atom.Choosing different parameters,the method can perform optimal symmetric(asymmetric)universal quantum cloning and optimal symmetric(asymmetric)phase-covariant cloning.Compared to previous schemes,our scheme is more insensitive to actual environmental noise and can get higher fidelity in a current cavity quantum electrodynamics system with an entangled state acting as a quantum channel than a single-photon pulse.
基金National Natural Science Foundation of China under Grant Nos.60678022 and 1070400the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No.20060357008+3 种基金Natural Science Foundation of Anhui Province under Grant No.070412060the Key Program of the Education Department of Anhui Province under Grant No.2006KJ070AThe Talent Foundation of Anhui UniversityAnhui Key Laboratory of Information Materials and Devices (Anhui University)
基金Supported by the National Natural Science Foundation of China under Grant Nos 11274010, 11204061, 11374085, 11104057, and 11204002, the Anhui Provincial Natural Science Foundation under Grant Nos 11040606M16 and 1408085MA16, the China Postdoctoral Science Foundation under Grant No 20110490825, the Key Project of Chinese Ministry of Education under Grant Nos 210092 and 211080, the Key Program of the Education Department of Anhui Province under Grant Nos KJ2012A244, KJ2011A243 and KJ2012A020, the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No 20113401110002, the ＇211＇ Project of Anhui University, and the Personnel Department of Anhui Province.
文摘The thermal entanglement in the spin-S Heisenberg XYZ model is studied in detail by using the entanglement measure of negativity. The effects of spin on the thermal entanglement, the threshold temperature, the critical uniform external magnetic field, the nonuniform external magnetic field and the＇, entanglement extremum are discussed, respectively. It is shown that with increasing spin, the entanglement will increase, and then decrease slowly. In addition, we find that entanglement will approach a constant Nc with the increase of DM interaction, the constant increases with the increase of spin, and both the threshold temperature Tc and critical uniform external magnetic field Bc will increase with the increasing spin. Thus high-spin system can inhibit the influence of the external environment better.
