题目：Floquet engineering in quantum systems

报告人：安钧鸿 兰州大学物理科学与技术学院   

地点： 教十二—201

时间： 3月26日，周五，15:30-16:30

摘要

Floquet engineering, i.e., coherent control via periodic driving, has become a highly versatile tool in quantum control. The main idea resides in that the concept of energy spectrum in static systems can be completely inherited as the quasienergy spectrum in periodically driven systems according to Floquet theory. Many efforts have been devoted to explore non-trivial effects induced by periodic driving on quantum systems. In this talk, I will report that interesting nonequilibrium quantum phase transitions (QPTs) can be triggered by engineering non-trivial band-gap structure and bound states in the quasi-energy spectrum using periodic driving. I will clarify this idea by two examples. One is to induce exotic topological QPT in both of Hermitian and non-Hermitian systems by periodic driving. A widely tunable number of topologically protected edge modes can be generated by a well-designed periodic driving, which relaxes greatly the experimental realization in the static case and improve the controllability of topological states of matter. Another is to induce non-equilibrium QPT in the total system consisting of open system and its environment by periodic driving. It is found that whenever the QPT manifested by the formation of midgap states in the quasienergy spectrum occurs, the decoherence of the open system can be suppressed. This opens an avenue to control decoherence by periodic driving.

个人简介

安钧鸿，兰州大学教授。2005年在兰州大学获博士学位，并留校工作。2006年至2007年在台湾成功大学从事博士后，2007年至2014年在新加坡国立大学从事研究员、访问研究员；2011年受聘为教授；2013年入选教育部新世纪优秀人才支持计划；2016年入选甘肃省飞天学者；2017年入选中央军委科技委国防科技创新特区主题专家组专家；2019年入选国家“万人计划”青年拔尖人才。主要从事开放量子系统、周期性驱动等系统的非平衡量子物理研究。

欢迎老师和同学参加！