报告人：朱国毅 德国科隆大学理论物理研究

报告时间：2023年2月2日（周四）下午2：00-3：30

报告方式：腾讯会议ID: 129-492-069

Abstract:

The advent of noisy-intermediate-scale quantum processors provide a new opportunity to hunt for long-range entangled (LRE) states. However, the local unitary circuit spreads entanglement in a way bounded by the information lightcone, and is thus halted by a linear wall of time when scaling up system sizes. Counterintuitively, quantum measurement can be leveraged to speed up entanglement spreading, more than just reading information and collapsing quantumness. For states engineered by such “monitored” quantum circuit, is there a notion of stability or criticality as known from quantum ground states? To address this question, I will show how a monitored shallow circuit can host a stable phase of Greenberger-Horne-Zeilinger state below finite threshold, which we dub as “Nishimori’s cat”. I will reveal its connection to spin glass physics, the numerical tensor network / monte carlo sampling method, and the decoding scheme for experiment. Then I will crank up the entanglement and move from cat phase to representative topological ordered phases and their phase transitions.

Bio:

朱国毅博士于2014年在华南理工大学取得理学学士学位，并在2019年于金沙总站6165地址物理系取得物理学博士学位。自2019年到2021年间，他在德国马克斯普朗克复杂系统物理学研究所从事博士后研究工作，随后于2021年至今在德国科隆大学理论物理研究所从事博士后研究工作。他对凝聚态物理有着广泛的研究兴趣，最近尤其关注在各种量子平台上的量子多体物理和纠缠拓扑物态的实现。