The Theoretical Study Of Multipartite Entanglement And Quantum Teleportation Of Surface Plasmon Polaritons

At the turn of the twentieth century,a series of crises arising in classical physics triggered a quantum revolution resulting in the birth of quantum mechanics.Quantum mechanics dominates the whole microworld.However,successful quantum mechanics accompanied by the counterintuitive property bothered Alert Einstein et al.There have been several sever debates between Einstein and Bohr about the irrealism and indeterminism with the culmination marked by the issue of the EPR paradox in 1935.In the immediate response,Bohr made bold claims not just for the descriptive adequacy of the quantum theory but also for its features of irrealism and indeterminism.Meanwhile,EPR paradox also brings us quantum entanglement phenomenon one of the most important concepts in quantum theory.In 1964,Bell presented Bell's theorem which states "no physical theory of local hidden variables can ever reproduce all of the predictions of quantum mechanics" and provides us a tool to test the property of nature ending the debates between Einstein and Bohr.Dating to the 1970s,obtaining complete control over single quantum systems enables us to make active control and operation over the microsystem resulting in the generation of quantum information.As a brand new subject with the application of quantum mechanics to the coding,storing,operating and controlling of information,quantum information shows us the great information-processing capabilities such as extending the channel capacity,speeding up the computation,guaranteeing the security of information in comparison with classical information-processing.With the potentiality of the existing physical systems sufficiently exploited in the quantum information scope,finding a new physical system involving quantum information-processing gets more and more pressing.With the development of quantum information-processing technology,in 1972 Freedman and Clauser have carried out the first actual Bell test starting a nearly half century explore of the property of nature.All such experimental violations require additional assumptions depending on their specific construction,making them vulnerable to so-called loopholes.My works during the undergraduate period involving the theoretical and experimental study of quantum information includes completing the quantum teleportation of surface plasmon polaritions and extending of Eberhard inequality to tripartite system.1.For the fair sampling loophole,the key point to close the loophole is either increasing detective and collect efficiency or expanding a new inequality without the fair-sampling assumption.Eberhard inequality is the second way to do the thing accounting for the imperfection of a detective device and incorporating the undetected event into the inequality.With respect to the bipartite system,Eberhard inequality decreased the limit of detective efficiency by 2/3 which allows us to discriminate the quantum theory and local reality theory.Eberhard inequality makes significant progress in contrast to the detective efficiency limit-0.8284 of the CHSH inequality lowering the difficulty for the Bell test.In order to make use of the merit of Eberhard inequality,we firstly expand the inequality to the tripartite system and find the analytical formula of the quantum states for different detective efficiencies.Our tripartite Eberhard inequality can lower the detective efficiency limit to 0.6 and background chaos tolerance limit are also calculated pertaining to different detective efficiencies.In spite of possessing the same detective efficiency limit with tripartite CH inequality,our tripartite Eberhard inequality will make a greater violation of the prediction of quantum theory beyond classical bound guaranteeing the base for the multipartite loophole-free Bell test.2.Quantum teleportation utilizing quantum entanglement verified by loophole-free Bell test can deliver quantum information from one location to another playing a key role in the future quantum information technology.As a critical part of quantum teleportation,traditional bell states measurement(BSM)device can only discriminate two bell states with half a hundred percent efficiencies.In our works,we utilize both the path and polarization degree of freedom of a single photon to encode the four Bell states to achieve the complete BSM with the beam displacers.Meanwhile,surface plasmon polaritons(SPPs)are collective excitations of free electrons propagating along a metal-dielectric interface showing a lot of quantum properties.Although some basic quantum properties of SPPs,such as the preservation of nonclassicality,the wave-particle duality of a single plasmon,the quantum interference of two plasmons,and the verification of entanglement generation,have been shown,more advanced quantum information protocols have yet to be demonstrated with SPPs,such as quantum teleportation which is a building block for future quantum technology.Here,we experimentally realize quantum state teleportation of single photons and single SPPs.The results of both quantum state and quantum process tomography confirm the quantum nature of the SPP teleportation.Our work shows that SPPs may be useful for realizing complex quantum protocols in a photonic-plasmonic hybrid quantum network bringing the new potentiality of quantum information processing in the future.