主讲人：费兆宇博士（中国工程物理研究院研究生院）

题目：Work Statistics across a Quantum Phase Transition

时间：2021年01月23日上午10：00

会议ID：（腾讯会议）242 471 391

联系人：黄亮

报告摘要：

Phase transitions are arguably the most interesting feature of statistical systems. For continuous phase transitions, the physical quantities of the system exhibit universal scaling behaviors near the critical temperature. Interestingly, at absolute zero temperature, critical phenomena also happen in some quantum many-body systems due to their quantum fluctuations, which is called quantum phase transition (QPT). The QPT can only be accessed by varying a physical parameter, such as magnetic field or pressure. Thus, we are talking about critical phenomena in nonequilibrium processes, different from it in equilibrium states.

In this report, we will introduce the Kibble-Zurek mechanism (KZM). It predicts that the topological defects in a system which is driven across its QPT critical point exhibit universal scaling behavior on the rate of the driving process. Moreover, we find that not only the expectation value of observables but also their fluctuations (characterized by work statistics) exhibit universal scaling behaviors too. And, in contrary to the KZM, these scaling behaviors are qualitatively different when the system ends away from or near the critical point. Our predictions are verified in an analytically solvable quantum many-body system, the one-dimensional transverse Ising model.

个人简介：

费兆宇，北京师范大学学士(物理，2015)；北京大学博士(物理，2020，导师：全海涛教授）。现中国工程物理研究院研究生院 “博强行动”访问学者。研究兴趣包括：非平衡态统计物理，量子多体系统的功分布，量子相变等。