题 目：Dissipative quantum phase transitions in the anisotropic Rabi model
报告人：Stefano Chesi ，北京计算科学研究中心（CSRC）
时 间：2023年6月25号（星期日）上午10:30
地点：理科楼LE201 邀请人：张瑜瑜
报告摘要：The quantum Rabi model describes a single qubit interacting with a bosonic mode and is one of the simplest models of light-matter interactions. Although it only has a few degrees of freedom, recent work has shown that in a suitable limit the model can realize a quantum phase transition, similar to superradiance in the Dicke model. In this talk we extend these results to include cavity decay and anisotropy, i.e., an unbalanced interaction where rotating- and counter-rotating terms have different weights. These aspects are important since typical realizations of the Rabi model (e.g., in circuit QED or trapped ions) are dissipative systems where a finite anisotropy appears naturally. We demonstrate that cavity dissipation produces a strong heating of the qubit, which has important consequences on the phase diagram and the critical properties of the system. Our findings indicate a general tendency of forming extreme non-equilibrium states in this single spin system, thus having broader implications for dissipative phase transitions of few-body systems.
报告人介绍：Dr. Stefano Chesi is an associate professor at the Beijing Computational Science Research Center (CSRC). He obtained his Ph.D. degree in Theoretical Condensed Matter Physics from Purdue University in 2007. Afterwards, he held postdoctoral positions at the University of Basel (Switzerland) and McGill University (Canada). In 2013 he became Research Scientist at RIKEN (Japan) and in 2014 he joined the faculty of CSRC, while being selected by the national recruitment program "1000 Young Thousand Talents of China". In 2021 he has been awarded by NSFC the Research Fund for International Excellent Young Scientists (RFIS-II). Dr. Chesi's research area is at the intersection of condensed matter physics and quantum information, with a special emphasis on the theoretical study of spin coherence in semiconductor nanostructures, spin qubits, and collective phenomena in quantum devices.
