量子信息-量子导引的实验研究与应用课件.pptx

1、Demonstration of Multisetting One-Way Einstein-Podolsky-Rosen Steering in Two-Qubit SystemsOutline1.Background introduction2.EPR steering criteria3.Multisetting One-way EPR steering4.Conclusion Outline1.Background introduction2.EPR steering criteria3.Multisetting One-way EPR steering4.Conclusion Loc

2、al hidden variableLocal hidden state Quantum nonloclaitya.measurement-device-dependentstate tomography projection measurement b.measurement-device-independent probability distribution Quantum nonloclaityprobability distributionsEntanglement A-to-B steeringBell non-localitycan notcan notcan not Quant

3、um nonloclaityQuantum non-localityAlice(can not be explained by)Bob(can not be explained by)Entanglement(non-separable)Local Hidden State ModelLocal Hidden State ModelBell non-localityLocal Hidden Variable ModelLocal Hidden Variable ModelEPR steering(Alice-to-Bob steering)Local Hidden Variable Model

4、Local Hidden State ModelWiseman et al.PRL 98,140402(2007);Jones et al.PRA 76,052116(2007)operational definitions Quantum nonloclaity Nonlocality,Steering,EntanglementFor Alice and Bob to demonstrate to Charlie that they can create entanglement between their labs.a).With no trust,they must demonstrat

5、e Bell-nonlocality.b).With a trustworthy Bob,Alice must show EPR-steering.c).With both trusted,all that is needed is Entanglement.EPR steering:Asymmetric Bell nonlocality A Bsteering B A steeringQuantum entanglement Quantum nonloclaity Application:one-way quantum information tasks.EntanglementSteeri

6、ngBell nonlocality(1)Alice sends a qubit to Bob(2)Bob announces the measu-rement directions to Alice (3)Alice measures and sends her results to Bob(4)Bob calculate the steering parameterAlice-to-Bob steeringEPR steering：The ability to affect the quantum state on one side with local measurements on t

7、he other sideYa.Xiao,et al.Phys.Rev.Lett.118,140404(2017)Quantum nonloclaityOutline1.Background introduction2.EPR steering criteria3.Multisetting One-way EPR steering4.Conclusion量子导引的度量子导引的度EPR steering criteriaInequalityMulti-measurement settingsWerner statesettings23 or 460.5393100.52361/2D.J.Saun

8、ders et al.Nat.Phys.6,845(2010)Defect：necessary and sufficient characterization of EPR-steering for Werner state量子导引的度量量子导引的度量P.Skrzypczyk et al.Phys.Rev.Lett.112,180404(2014).Steerable weightDefect：w=1 for all pure entanglement states量子导引的度量子导引的度EPR steering criteriaVon Neumann entropy 量子导引的度量量子导引的

9、度量M.Piani et al.Phys.Rev.Lett.114,060404(2015).Steering robustnessDifficulty:need take all kinds of noise into cosideration量子导引的度量子导引的度EPR steering criteria noise assemblagesteering robustness of the assemblage A defined as:is unsteerable s.t.unsteerable！The length of Bloch vectorsteering radiusStee

10、ring radius(our methods)Construction of LHSsteerable！Wu et al.Sci.Rep.4,4291(2014)量子导引的度量子导引的度EPR steering criteriaNecessary and sufficient criteriaOutline1.Background introduction2.EPR steering criteria3.Multisetting One-way EPR steering4.Conclusiontwo-settingqubit-qutrit systemu MotivationPhys.Rev

11、.Lett.116,160403(2016).Phys.Rev.Lett.116,160404(2016).Nat.Photon 6,596(2012).Gaussian measurement One-way steering with infinite measurement settingsThe demonstration of genuine one-way steering with multimeasurement settings in the simplest bipartite system are still lacking.Experimental difficulty

12、:verify the unsteerable genuine one-way steering state new criteria to characterize the steerabilitySolutions：Entangled p 1/3unsteerable from Bob to AliceUnsteerable p 1/2Separated p 1/2We consider the class of two-qubit statesJ.Bowles et al.Phys.Rev.A 93,022121(2016)One-way steering with infinite m

13、easurement settingsFidelity=0.995u experimental realization One-way steering with infinite measurement settingsYa Xiao et al.Phys.Rev.Lett.118,140404(2017)twomeasurement settingsYa Xiao et al.Phys.Rev.Lett.118,140404(2017)Mean fidelity 99.4%One-way steering with infinite measurement settingsRed:one

14、way steerable Blue:bi-unsteerableBrown:bi-steeralbethreemeasurement settingsRed:one way steerable Blue:bi-unsteerableBrown:bi-steeralbesteerable One-way steering with infinite measurement settingsDemonstration of multisetting one-way EPR-steering in a qubit-qubit systemthreemeasurement settings One-

15、way steering with infinite measurement settingsOutline1.Background introduction2.EPR steering criteria3.Multisetting One-way EPR steering4.Conclusion We provide a necessary and sufficient criterion,steering radius,to quantify steerability.We demonstration of one-way EPR steering in a qubit-qubit systerm even for infinite-measurement.Our work provides a more essential and intuitive way to understand the asymmetric characteristic of EPR steering.123 One-way steering with infinite measurement settings“编辑推荐”文章的推介信 One-way steering with infinite measurement settings