报告题目:

Large Scale Photonic Quantum Walks for Quantum Simulation

报告时间：2020年12月31日（星期四）15:30-16:30

报告地点：翡翠湖校区科教楼A1706

报 告 人：许小冶 教授

工作单位：中国科学技术大学

举办单位：电子科学与应用物理学院

报告人简介：

许小冶，2007年本科毕业于304永利集团官网入口应用物理学专业，2013年在中国科学技术大学物理学院完成博士学位，目前任职中国科学技术大学特任教授。长期从事基于光子的量子模拟和量子力学基本问题的实验研究。获得2013年度中国科学院院长优秀奖，2016年入选首批博士后创新人才支持计划，入选2020年度中国科学院青年创新促进会，2020年获得基金委优秀青年项目支持。博士学位论文入选2014年度中国科学院优秀博士论文，并受邀在《Springer Theses - Recognizing Outstanding Ph.D. Research》系列丛书出版。

报告简介：

  Quantum walk has been being an important participant in completing quantum information tasks, and it has been proved that as a quantum computation primitive universal quantum computation can be constructed based on quantum walks. On account of working at room temperature and excellent quantum coherence, photonic systems have been being an important implementation of quantum walks. While there have developed various architectures for photonic quantum walks till now, the limitations in system scale, controllability of nodes, and numbers of adopted photons are still preventing the applications in the future quantum information tasks. Here, we will report a novel protocol for implementing photonic quantum walks based on the time-multiplexing architecture. By introducing the heralded single-photon as the walker, we report a single-photon 50-step Hadamard quantum walk with fidelity as high as 0.945. Furthermore, using the large scale photonic quantum walk platform, we perform a few experiments on quantum simulation: direct measurement of the topological invariants in quantum walks based on reconstructing the eigenstates of the systems; experimentally studying the quantum non-equilibrium dynamics based on quantum walks, and observing the dynamic quantum phase transition via measuring the dynamic topological order parameter; reconstructing the Berry curvature on the momentum-time manifold to read out the dynamical Chern number in the non-equilibrium quantum dynamics, subsequently completely classifying the quenched quantum walks.