Entanglement thresholds for displaying the quantum nature of teleportation

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• 作者：Luis Roa^a ; ^{lroa@udec.cl" class="auth_mail" title="E-mail the corresponding author} ; Robinson Gó ; mez^a ; ^b ; Ariana Muñ ; oz^a ; ^b ; Gautam Rai^c ; Matthias Hecker^d
• 关键词：Teleportation ; Average fidelity ; Entanglement threshold ; XX-state ; Noisy channel
• 刊名：Annals of Physics
• 出版年：2016
• 出版时间：August 2016
• 年：2016
• 卷：371
• 期：Complete
• 页码：228-238
• 全文大小：418 K

文摘

A protocol for transferring an unknown single qubit state evidences quantum features when the average fidelity of the outcomes is, in principle, greater than mmlsi1" class="mathmlsrc">mulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0003491616300513&_mathId=si1.gif&_user=111111111&_pii=S0003491616300513&_rdoc=1&_issn=00034916&md5=587530e492065414aaf432f73fd8c9b2" title="Click to view the MathML source">2/3mathContainer hidden">mathCode"><math altimg="si1.gif" overflow="scroll"><mn>2mn><mo>/mo><mn>3mn>math>. We propose to use the m>probabilistic and unambiguous state extraction scheme  m> as a mechanism to redistribute the fidelity in the outcome of the standard teleportation when the process is performed with an mmlsi2" class="mathmlsrc">mulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0003491616300513&_mathId=si2.gif&_user=111111111&_pii=S0003491616300513&_rdoc=1&_issn=00034916&md5=572e9f8e627479b45af083fccb86368f" title="Click to view the MathML source">XmathContainer hidden">mathCode"><math altimg="si2.gif" overflow="scroll"><mi>Xmi>math>-state as a noisy quantum channel. We show that the entanglement of the channel is necessary but not sufficient in order for the average fidelity mmlsi3" class="mathmlsrc">mulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0003491616300513&_mathId=si3.gif&_user=111111111&_pii=S0003491616300513&_rdoc=1&_issn=00034916&md5=8b1ae0768081c4360784ec690d6dd543" title="Click to view the MathML source">f_XmathContainer hidden">mathCode"><math altimg="si3.gif" overflow="scroll"><msub><mrow><mi>fmi>mrow><mrow><mi>Xmi>mrow>msub>math> to display quantum features, i.e., we find a threshold mmlsi4" class="mathmlsrc">mulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0003491616300513&_mathId=si4.gif&_user=111111111&_pii=S0003491616300513&_rdoc=1&_issn=00034916&md5=06e379f70323289c095ae9577ebb72f0" title="Click to view the MathML source">C_XmathContainer hidden">mathCode"><math altimg="si4.gif" overflow="scroll"><msub><mrow><mi>Cmi>mrow><mrow><mi>Xmi>mrow>msub>math> for the concurrence of the channel. On the other hand, if the mechanism for redistributing fidelity is successful then we find a filterable outcome with average fidelity mmlsi5" class="mathmlsrc">mulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0003491616300513&_mathId=si5.gif&_user=111111111&_pii=S0003491616300513&_rdoc=1&_issn=00034916&md5=bebd10761d220289ede516ae5ca60ef7" title="Click to view the MathML source">f_X,0mathContainer hidden">mathCode"><math altimg="si5.gif" overflow="scroll"><msub><mrow><mi>fmi>mrow><mrow><mi>Xmi><mo>,mo><mn>0mn>mrow>msub>math> that can be greater than mmlsi3" class="mathmlsrc">mulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0003491616300513&_mathId=si3.gif&_user=111111111&_pii=S0003491616300513&_rdoc=1&_issn=00034916&md5=8b1ae0768081c4360784ec690d6dd543" title="Click to view the MathML source">f_XmathContainer hidden">mathCode"><math altimg="si3.gif" overflow="scroll"><msub><mrow><mi>fmi>mrow><mrow><mi>Xmi>mrow>msub>math>. In addition, we find the threshold concurrence of the channel mmlsi7" class="mathmlsrc">mulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0003491616300513&_mathId=si7.gif&_user=111111111&_pii=S0003491616300513&_rdoc=1&_issn=00034916&md5=cd3c983ee3dbb41744c0b4c737e9ea84" title="Click to view the MathML source">C_X,0mathContainer hidden">mathCode"><math altimg="si7.gif" overflow="scroll"><msub><mrow><mi>Cmi>mrow><mrow><mi>Xmi><mo>,mo><mn>0mn>mrow>msub>math> in order for the average fidelity mmlsi5" class="mathmlsrc">mulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0003491616300513&_mathId=si5.gif&_user=111111111&_pii=S0003491616300513&_rdoc=1&_issn=00034916&md5=bebd10761d220289ede516ae5ca60ef7" title="Click to view the MathML source">f_X,0mathContainer hidden">mathCode"><math altimg="si5.gif" overflow="scroll"><msub><mrow><mi>fmi>mrow><mrow><mi>Xmi><mo>,mo><mn>0mn>mrow>msub>math> to display quantum features and surprisingly, the threshold concurrence mmlsi7" class="mathmlsrc">mulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0003491616300513&_mathId=si7.gif&_user=111111111&_pii=S0003491616300513&_rdoc=1&_issn=00034916&md5=cd3c983ee3dbb41744c0b4c737e9ea84" title="Click to view the MathML source">C_X,0mathContainer hidden">mathCode"><math altimg="si7.gif" overflow="scroll"><msub><mrow><mi>Cmi>mrow><mrow><mi>Xmi><mo>,mo><mn>0mn>mrow>msub>math> can be less than mmlsi4" class="mathmlsrc">mulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0003491616300513&_mathId=si4.gif&_user=111111111&_pii=S0003491616300513&_rdoc=1&_issn=00034916&md5=06e379f70323289c095ae9577ebb72f0" title="Click to view the MathML source">C_XmathContainer hidden">mathCode"><math altimg="si4.gif" overflow="scroll"><msub><mrow><mi>Cmi>mrow><mrow><mi>Xmi>mrow>msub>math>. Even more, we find some special cases for which the threshold values become zero.