题目： Classical emulation of quantum states

报告人：Svetlana Mikhalycheva 研究员 (白俄罗斯国家科学院斯捷潘诺夫物理研究所)

时 间：2024年9月13号（周五）下午14：00-16：00

地 点：线下-良乡校区，物理实验中心229会议室

摘要：

Many quantum-optical phenomena (including Hong-Ou-Mandel effect, violation of Bell inequalities, multiphoton interference for NOON states) require preparation of states with pronounced non-classical properties. Sometimes, such genuine quantum states are temporarily unavailable or too expensive for generation. The situation is quite typical for design of educational demonstrational setups and for preliminary testing of the measurement apparatus during design of quantum experiments. We propose a methodology to emulate quantum phenomena arising from nonclassical quantum states using only a finite set of mixtures of coherent states. The approach is based on the ability to decompose density operators of optical field in terms of coherent states (Glauber-Sudarshan representation and its approximations with a finite number of coherent states). Such a decomposition has demonstrated its usefulness in quantum tomography and allowed one to avoid calibrating detectors. Here, we solve an opposite problem: using a known but unavailable state, one needs to reproduce (emulate) measurement results with it.

We present a simple procedure to experimentally carry out quantum-state emulation with coherent states, illustrate it emulating multiphoton NOON states with few phase-averaged coherent states, and demonstrate its capabilities in observing fundamental quantum mechanical effects, such as Hong-Ou-Mandel effect, violating Bell inequalities and witnessing quantum nonclassicality. Further, we show that, if the measured signal is constructed from normal-ordered field operators, one can scale the amplitudes of the used coherent states and emulate single-photon level effects with bright states. The result is demonstrated by numerical modeling of the bright-state emulation of Hong-Ou-Mandel interference, phase measurements with NOON states and specifically structured “revivals” in Jaynes-Cummings model. We also show that certain classes of bright non-classical states can be efficiently emulated by our technique independently of the average photon number of these states.

简历：

Svetlana Mikhalycheva is a senior researcher in B.I.Stepanov Institute of Physics，National academy of sciences of Belarus. She has published more than 20 papers in top journals in physics, such as Phys.Rev , npj Quantum Inf. and so on. Her research covers: classic simulation of quantum state. She has finished projects like EU Horizon 2020 project, BRFFR-KOREA.

联系方式：shenglizhangustc@126.com

邀请人： 张胜利

网 址：/

承办单位：物理学院、先进光电量子结构设计与测量教育部重点实验室