在两体混合压缩态中的蒸馏纠缠-论文.pdf

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1、2014年8月湖南师范大学自然科学学报Vo1．37No．4第37卷第4期JournalofNaturalScienceofHunanNormalUniversityAug．，2014DistillabilityEntanglementintheBipartiteMixedSqueezedStatesHUANGJiang，LIUXiang(CollegeofPhysicsandInformationScience，HunanNormalUniversity，Changsha410081，China)AbstractTheproblemofentanglementwithdi

2、stillabilityofatwomixedsqueezedstatesusingbeamsplittersanddetectiontechniqueswerestudied．Thenegativityandlogarithmicnegativitytomeasuretheentanglementbeforeandafterdistillabilitywereused．Theresultsshowthatthevalueofsqueezedparam—eterisanimportantfactortoefecttheentanglement．Furthermore，th

3、etransmissioncoeficientsofthephoton—subtractionbeamsplitterwerealsoconsidered．Keywordsentanglement；distiUability；squeezedstate；logarithmicnegativity中图分类号0431．2文献标识码A文章编号1000-2537(2014)04-0051-06在两体混合压缩态中的蒸馏纠缠黄江，刘翔(湖南师范大学物理与信息科学学院，中国长沙410081)摘要利用分束器和探测技术研究了在两体混合压缩态条件下蒸馏性与纠缠的关系问题，利用负度和对数负度测

4、量蒸馏前后的纠缠变化．研究结果表明，压缩参数的取值是影响纠缠的一个重要因素．文中还研究了光子扣除分束器的透射系数对纠缠的影响．关键词纠缠；蒸馏；压缩态；对数负度Entanglementisknowntoplayakeyroleinmanyquantuminformationprocesses，includingquantumstatetel—eportation㈦，cryptographickeydistribution[，classicalcommunicationoverquantumchannels，quantumer．rorcorrection[anddistri

5、butedcomputation[8_9]．However，entanglementisrelativelyeasytobedegradedasan，interactionofuncontrollableenvironment．Inordertoovercometheshortageofentanglementdecay，manyprotocolshavebeenutilizedtokeeporrevivalentanglement．Forexample，thenon—Markovianstrongcouplingmemoryeffectisusedtorevivalen

6、tanglementinRef[1O一12]；Entanglementpurificationordistillabilityarealsopopulartobeappliedtoslowdownitsdecay，andSOon．Entanglementdistillabilityisamethodtocreateentangledbipartitesofhigherentanglementfromthatimperfectlyentangledpairsinthewayoflocaloperationsandclassicalcommunica—tion．Ontheco

7、ntrary，therearealsomanyworksshowsthatthedistillabilitycanrestrainentanglement．SongWeietalhadfoundthattheentanglementcouldbesuddendeathinthelocaldephasingprocessunderdistillabilityin收稿日期：2013．12-11基金项目：ProjectssupportedbytheNationalNaturalScienceFoundationofChina(110