恒元物理學(xué)講座（第088期）：Multipartite Gaussian steering: Monogamy constraints and quantum cryptography applications

發(fā)布時間：2017-06-16 瀏覽：次

講座題目：恒元物理學(xué)講座（第088期）：Multipartite Gaussian steering: Monogamy constraints and quantum cryptography applications

講座人:何瓊毅研究員

講座時間：10:30

講座日期：2017-6-16

地點：長安校區(qū) 物理學(xué)與信息技術(shù)學(xué)院六層學(xué)術(shù)報告廳（致知樓3623-3624）

主辦單位：物理學(xué)與信息技術(shù)學(xué)院

講座內(nèi)容：The concept of quantum steering was originally introduced bySchr?dinger to describe the “spooky action-at-a-distance” effect noted in theEinstein-Podolsky-Rosen (EPR) paradox, whereby local measurements performed onone party apparently adjust (steer) the state of another distant party. Weextend to study multipartite steering distributed over many parties. First, wederived inequalities to demonstrate multipartite EPR steering [1] which hasbeen experimentally tested with optical network up to eight modes [2]. Second,we derived laws for the distribution of quantum steering among differentparties in multipartite Gaussian states under Gaussian measurements [3]. Veryrecently, the monogamy relations for Gaussian steerability have beendemonstrated for four-mode square Gaussian cluster state [4]. Our results pindown the role of multipartite steering for quantum communication.

[1] Q. Y. He & M. D. Reid, Phys. Rev. Lett. 111, 250403 (2013).

[2] S. Armstrong et al., Nature Physics 11, 167-172 (2015).

[3] Y. Xiang et al., Phys. Rev. A 95, 010101R (2017).

[4] X. W. Deng et al., Phys. Rev. Lett. 118, 230501 (2017).