本文主要研究内容
作者王文丽（2019）在《纠缠witnesses及其构造》一文中研究指出：识别纠缠态是量子信息科学的基本问题,而纠缠witness判据是检测纠缠性的两个充要判据之一.如果W是复Hilbert空间H(?)K上非正的可观测量(即自伴算子),且对所有的纯态P∈P1(H)和Q ∈P1(K)有Tr(W(P(?)Q))≥ 0,则W是—个纠缠witness.纠缠witness判据断言复合系统H(?)K上的—个态ρ是纠缠的当且仅当存在某个纠缠witness W使得Tr(Wρ)<0.所以,知道的纠缠witness越多,可识别的纠缠态就越多.但构造所有的纠缠witness是一个非多项式复杂问题.本文给出了两种构造纠缠witness的新方法:(1)对任意两列可观测量{Ek}k=1∞匕和{Fk}k=1∞,如果对所有的k,=1,2,..…,都有Tr(EkEl)=Tr(FkFl)=δkl且∑是k=1∞Ek(?)Fk在WOT(弱算子拓扑)下收敛到有界算子,则只要W=I-∑k=1∞Ek(?)Fk不是正算子W就是一个纠缠witness.(2)令{π1,π2}是(1,2,...,n)的一对非恒等的置换,如果{π1,π2}具有性质(C),则Wn,π1,π2 =(n-3)∑k=1n Ekk(?)Ekk+Σk=1n Ekk(?)Eπ1(kk),π1(kk)+Σk=1n Ekk(?)Eπ2(k),π2(k)-Σk≠l Ekl(?)Ekl是纠缠witness.本文还对用这两种方法构造的纠缠witness的可分解性和最优性等性质进行了讨论.
Abstract
shi bie jiu chan tai shi liang zi xin xi ke xue de ji ben wen ti ,er jiu chan witnesspan ju shi jian ce jiu chan xing de liang ge chong yao pan ju zhi yi .ru guo Wshi fu Hilbertkong jian H(?)Kshang fei zheng de ke guan ce liang (ji zi ban suan zi ),ju dui suo you de chun tai P∈P1(H)he Q ∈P1(K)you Tr(W(P(?)Q))≥ 0,ze Wshi —ge jiu chan witness.jiu chan witnesspan ju duan yan fu ge ji tong H(?)Kshang de —ge tai ρshi jiu chan de dang ju jin dang cun zai mou ge jiu chan witness Wshi de Tr(Wρ)<0.suo yi ,zhi dao de jiu chan witnessyue duo ,ke shi bie de jiu chan tai jiu yue duo .dan gou zao suo you de jiu chan witnessshi yi ge fei duo xiang shi fu za wen ti .ben wen gei chu le liang chong gou zao jiu chan witnessde xin fang fa :(1)dui ren yi liang lie ke guan ce liang {Ek}k=1∞bi he {Fk}k=1∞,ru guo dui suo you de k,=1,2,..…,dou you Tr(EkEl)=Tr(FkFl)=δklju ∑shi k=1∞Ek(?)Fkzai WOT(ruo suan zi ta pu )xia shou lian dao you jie suan zi ,ze zhi yao W=I-∑k=1∞Ek(?)Fkbu shi zheng suan zi Wjiu shi yi ge jiu chan witness.(2)ling {π1,π2}shi (1,2,...,n)de yi dui fei heng deng de zhi huan ,ru guo {π1,π2}ju you xing zhi (C),ze Wn,π1,π2 =(n-3)∑k=1n Ekk(?)Ekk+Σk=1n Ekk(?)Eπ1(kk),π1(kk)+Σk=1n Ekk(?)Eπ2(k),π2(k)-Σk≠l Ekl(?)Eklshi jiu chan witness.ben wen hai dui yong zhe liang chong fang fa gou zao de jiu chan witnessde ke fen jie xing he zui you xing deng xing zhi jin hang le tao lun .
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论文详细介绍
论文作者分别是来自太原理工大学的王文丽，发表于刊物太原理工大学2019-07-26论文，是一篇关于空间论文,线性算子论文,纠缠态论文,纠缠论文,置换论文,太原理工大学2019-07-26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，资料来自太原理工大学2019-07-26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。