本文主要研究内容
作者孙文洋（2019）在《开放系统中量子导引及其相关问题研究》一文中研究指出：量子非局域关联(量子纠缠、量子导引(Einstein-Podolsky-Rosen导引)和Bell非定域性)在许多量子通信和量子计算任务中发挥着重要作用,也是实现量子信息任务的重要资源。然而在实际的量子系统中,量子系统不可避免与它周围的外部噪声发生相互耦合作用,从而导致系统的量子非局域关联快速衰退甚至陨灭,即所谓的退相干现象。故研究开放系统中量子非局域关联的动力学行为、探索如何抑制环境所带来的退相干效应以及众多量子资源之间的内在关系对促进人们更好地去实现量子信息任务具有重要的意义。本毕业论文主要研究开放系统中量子非局域关联的动力学行为及有效地恢复系统在non-Markovian环境中所丢失的Einstein-Podolsky-Rosen(EPR)导引问题;研究在非惯性系框架下Unruh效应对EPR导引的影响以及其重新分配情况;探索复合系统中量子资源之间的内在联系。研究成果如下:(1)研究了在两粒子量子系统中,单一子系统与局域噪声信道相互作用后系统的非局域关联的动力学行为。研究结果表明:所有的纠缠纯态和最大纠缠演化态都是可导引的,并不是每一个纠缠演化态都具有可导引能力,一些可导引的量子态不具备Bell非定域性。此外,在比特翻转(bit flip(BF))和相位翻转(phase flip(PF))信道中,EPR导引随着退相干强度的增强先会经历“猝死”现象,随后立即重新获得。当初始共享的态是纠缠纯态时,所有经过PF信道和相位阻尼(phase damping(PD))信道的纠缠演化态都是可导引的且满足Bell非定域性。在BF信道中,所有可导引的态都具有Bell非定域性,但存在一些纠缠态不能被利用去实现EPR导引。然而,当共享的初态为纠缠混合态时,得到的结果却不同于初态为纠缠纯态。其次,纠缠混合态的可导引能力弱于纠缠纯态的可导引能力。(2)探讨了在non-Markovian环境中EPR导引的动力学行为,以及如何有效地去恢复量子态丢失的可导引能力。我们考虑了两种不同的情况:一个子系统与non-Markovian环境相耦合;整个系统与non-Markovian环境相耦合。结果表明:在相同的条件下,量子纠缠会出现准周期的复活,然而EPR导引则无法重新获得,且复活的量子纠缠也不能用来实现EPR导引。随后我们基于弱测量操作给出了恢复non-Markovian环境中量子系统的EPR导引方案。本方案包括在系统和non-Markovian环境相互作用前,对其系统进行预先弱测量操作,在相互作用后实行反转测量操作。结果表明:该方案能够有效地恢复量子态的可导引能力及其保真度。此外,弱测量强度越大,该方案恢复EPR导引的效果越好。(3)研究了非惯性系框架中EPR导引的动力学行为和EPR导引的重新分配情况。我们探讨了在平直时空中由Alice持有的粒子A和另一个在Rindler时空中由Bob持有的与粒子A相纠缠的粒子B的情况。结果表明:由Alice到Bob的EPR导引由于受到了Bob加速度所引起的Unruh效应的影响而退化。此外,我们发现EPR导引具有不对称性,且EPR导引的不对称性随Unruh效应的增强而变大。EPR导引的再分配结果表明:由Alice到Bob减少的物理可访问的EPR导引被分配到物理不可访问的EPR导引(由Alice到anti-Bob的导引或由Bob到anti-Bob的导引)。EPR导引的重新分配完全不同于量子纠缠和量子失谐,Alice到anti-Bob的EPR导引和Bob到anti-Bob的EPR导引,仅有一个EPR导引随加速度参数的增加而“再生”,这意味着它们不能同时幸存。也就是说,在非惯性系框架中EPR导引的一夫一妻制关系仍然成立。因此,我们认为EPR导引也可以作为相对论框架下长距离量子保密通信的重要资源之一。(4)为了揭示量子资源背后隐藏的内在关系。我们研究了在类W态系统中量子资源之间的内在相互关系。结果表明:相干程度、共生纠缠、Bell非定域性和量子态纯度之间具有某种特定的量化关系。考虑由类W态衍生而来的两体子系统的Bell非局域态(BNBSs)和Bell局域态(BLBSs:满足Bell Clauser-Horne-Shimony-Holt(Bell-CHSH)不等式),我们得到了与之相对应的相干程度和共生纠缠的定量关系式,也得到了相干程度、共生纠缠和纯度三者之间的精确定量关系式。此外,在两种特定的方案中:噪声信道中的类W态和重整化自旋为1/2海森堡(Heisenberg)XXZ模型,其对应的相干程度也与其共生纠缠有着特定的量化关系。
Abstract
liang zi fei ju yu guan lian (liang zi jiu chan 、liang zi dao yin (Einstein-Podolsky-Rosendao yin )he Bellfei ding yu xing )zai hu duo liang zi tong xin he liang zi ji suan ren wu zhong fa hui zhao chong yao zuo yong ,ye shi shi xian liang zi xin xi ren wu de chong yao zi yuan 。ran er zai shi ji de liang zi ji tong zhong ,liang zi ji tong bu ke bi mian yu ta zhou wei de wai bu zao sheng fa sheng xiang hu ou ge zuo yong ,cong er dao zhi ji tong de liang zi fei ju yu guan lian kuai su cui tui shen zhi yun mie ,ji suo wei de tui xiang gan xian xiang 。gu yan jiu kai fang ji tong zhong liang zi fei ju yu guan lian de dong li xue hang wei 、tan suo ru he yi zhi huan jing suo dai lai de tui xiang gan xiao ying yi ji zhong duo liang zi zi yuan zhi jian de nei zai guan ji dui cu jin ren men geng hao de qu shi xian liang zi xin xi ren wu ju you chong yao de yi yi 。ben bi ye lun wen zhu yao yan jiu kai fang ji tong zhong liang zi fei ju yu guan lian de dong li xue hang wei ji you xiao de hui fu ji tong zai non-Markovianhuan jing zhong suo diu shi de Einstein-Podolsky-Rosen(EPR)dao yin wen ti ;yan jiu zai fei guan xing ji kuang jia xia Unruhxiao ying dui EPRdao yin de ying xiang yi ji ji chong xin fen pei qing kuang ;tan suo fu ge ji tong zhong liang zi zi yuan zhi jian de nei zai lian ji 。yan jiu cheng guo ru xia :(1)yan jiu le zai liang li zi liang zi ji tong zhong ,chan yi zi ji tong yu ju yu zao sheng xin dao xiang hu zuo yong hou ji tong de fei ju yu guan lian de dong li xue hang wei 。yan jiu jie guo biao ming :suo you de jiu chan chun tai he zui da jiu chan yan hua tai dou shi ke dao yin de ,bing bu shi mei yi ge jiu chan yan hua tai dou ju you ke dao yin neng li ,yi xie ke dao yin de liang zi tai bu ju bei Bellfei ding yu xing 。ci wai ,zai bi te fan zhuai (bit flip(BF))he xiang wei fan zhuai (phase flip(PF))xin dao zhong ,EPRdao yin sui zhao tui xiang gan jiang du de zeng jiang xian hui jing li “cu si ”xian xiang ,sui hou li ji chong xin huo de 。dang chu shi gong xiang de tai shi jiu chan chun tai shi ,suo you jing guo PFxin dao he xiang wei zu ni (phase damping(PD))xin dao de jiu chan yan hua tai dou shi ke dao yin de ju man zu Bellfei ding yu xing 。zai BFxin dao zhong ,suo you ke dao yin de tai dou ju you Bellfei ding yu xing ,dan cun zai yi xie jiu chan tai bu neng bei li yong qu shi xian EPRdao yin 。ran er ,dang gong xiang de chu tai wei jiu chan hun ge tai shi ,de dao de jie guo que bu tong yu chu tai wei jiu chan chun tai 。ji ci ,jiu chan hun ge tai de ke dao yin neng li ruo yu jiu chan chun tai de ke dao yin neng li 。(2)tan tao le zai non-Markovianhuan jing zhong EPRdao yin de dong li xue hang wei ,yi ji ru he you xiao de qu hui fu liang zi tai diu shi de ke dao yin neng li 。wo men kao lv le liang chong bu tong de qing kuang :yi ge zi ji tong yu non-Markovianhuan jing xiang ou ge ;zheng ge ji tong yu non-Markovianhuan jing xiang ou ge 。jie guo biao ming :zai xiang tong de tiao jian xia ,liang zi jiu chan hui chu xian zhun zhou ji de fu huo ,ran er EPRdao yin ze mo fa chong xin huo de ,ju fu huo de liang zi jiu chan ye bu neng yong lai shi xian EPRdao yin 。sui hou wo men ji yu ruo ce liang cao zuo gei chu le hui fu non-Markovianhuan jing zhong liang zi ji tong de EPRdao yin fang an 。ben fang an bao gua zai ji tong he non-Markovianhuan jing xiang hu zuo yong qian ,dui ji ji tong jin hang yu xian ruo ce liang cao zuo ,zai xiang hu zuo yong hou shi hang fan zhuai ce liang cao zuo 。jie guo biao ming :gai fang an neng gou you xiao de hui fu liang zi tai de ke dao yin neng li ji ji bao zhen du 。ci wai ,ruo ce liang jiang du yue da ,gai fang an hui fu EPRdao yin de xiao guo yue hao 。(3)yan jiu le fei guan xing ji kuang jia zhong EPRdao yin de dong li xue hang wei he EPRdao yin de chong xin fen pei qing kuang 。wo men tan tao le zai ping zhi shi kong zhong you Alicechi you de li zi Ahe ling yi ge zai Rindlershi kong zhong you Bobchi you de yu li zi Axiang jiu chan de li zi Bde qing kuang 。jie guo biao ming :you Alicedao Bobde EPRdao yin you yu shou dao le Bobjia su du suo yin qi de Unruhxiao ying de ying xiang er tui hua 。ci wai ,wo men fa xian EPRdao yin ju you bu dui chen xing ,ju EPRdao yin de bu dui chen xing sui Unruhxiao ying de zeng jiang er bian da 。EPRdao yin de zai fen pei jie guo biao ming :you Alicedao Bobjian shao de wu li ke fang wen de EPRdao yin bei fen pei dao wu li bu ke fang wen de EPRdao yin (you Alicedao anti-Bobde dao yin huo you Bobdao anti-Bobde dao yin )。EPRdao yin de chong xin fen pei wan quan bu tong yu liang zi jiu chan he liang zi shi xie ,Alicedao anti-Bobde EPRdao yin he Bobdao anti-Bobde EPRdao yin ,jin you yi ge EPRdao yin sui jia su du can shu de zeng jia er “zai sheng ”,zhe yi wei zhao ta men bu neng tong shi xing cun 。ye jiu shi shui ,zai fei guan xing ji kuang jia zhong EPRdao yin de yi fu yi qi zhi guan ji reng ran cheng li 。yin ci ,wo men ren wei EPRdao yin ye ke yi zuo wei xiang dui lun kuang jia xia chang ju li liang zi bao mi tong xin de chong yao zi yuan zhi yi 。(4)wei le jie shi liang zi zi yuan bei hou yin cang de nei zai guan ji 。wo men yan jiu le zai lei Wtai ji tong zhong liang zi zi yuan zhi jian de nei zai xiang hu guan ji 。jie guo biao ming :xiang gan cheng du 、gong sheng jiu chan 、Bellfei ding yu xing he liang zi tai chun du zhi jian ju you mou chong te ding de liang hua guan ji 。kao lv you lei Wtai yan sheng er lai de liang ti zi ji tong de Bellfei ju yu tai (BNBSs)he Bellju yu tai (BLBSs:man zu Bell Clauser-Horne-Shimony-Holt(Bell-CHSH)bu deng shi ),wo men de dao le yu zhi xiang dui ying de xiang gan cheng du he gong sheng jiu chan de ding liang guan ji shi ,ye de dao le xiang gan cheng du 、gong sheng jiu chan he chun du san zhe zhi jian de jing que ding liang guan ji shi 。ci wai ,zai liang chong te ding de fang an zhong :zao sheng xin dao zhong de lei Wtai he chong zheng hua zi xuan wei 1/2hai sen bao (Heisenberg)XXZmo xing ,ji dui ying de xiang gan cheng du ye yu ji gong sheng jiu chan you zhao te ding de liang hua guan ji 。
论文参考文献
论文详细介绍
论文作者分别是来自安徽大学的孙文洋，发表于刊物安徽大学2019-07-03论文，是一篇关于噪声信道论文,开放系统论文,导引论文,量子资源论文,弱测量操作论文,安徽大学2019-07-03论文的文章。本文可供学术参考使用，各位学者可以免费参考阅读下载，文章观点不代表本站观点，资料来自安徽大学2019-07-03论文网站，若本站收录的文献无意侵犯了您的著作版权，请联系我们删除。