Controlling topological quantum matter with vacuum electromagnetic fields

报告题目: Controlling topological quantum matter with vacuum electromagnetic fields

报告人:聂伟博士   日本理化学研究所




报告摘要:Topological matter is an important discovery in modern physics and inspires a broad range of studies, including topological quantum computation and topological photonics. Recently, the interaction between quantum light and topological matter receives much attention, which may open a way for topological quantum optics. In this talk, I will show the potential to manipulate topological quantum matter with vacuum electromagnetic fields. In a one-dimensional topological atom array globally coupling to electromagnetic fields, the bandgap is not able to protect stable topological phase even though the light-matter coupling is weak. This makes the bandgap-enabled topological robustness, usually for local imperfections, fragile for electromagnetic environment. However, in electromagnetic vacuum, the spectrum width of the topological system sets an upper bound for symmetry-protected light-matter coupling. A dissipative topological phase transition appears when the light-matter coupling reaches a critical value related to spectrum width of the topological matter. As a consequence, the spectrum width becomes a hallmark for topological protection in electromagnetic environment. Moreover, the topological robustness in electromagnetic environment is captured by a dissipationless window, which protects the system from many types of disorder, including atomic frequency and atom-atom interaction. Experimental possibility in superconducting quantum circuits is also considered.

报告人简介:聂伟,博士,日本理化学研究所博士后研究员。2017年从新加坡国立大学量子技术中心(Centre for Quantum Technologies)获得博士学位。2017年至2019年在清华大学微电子所从事博士后研究工作,获清华大学博士后支持计划资助。2020年,加入日本理化学研究所理论量子物理实验室。其主要研究领域包括量子模拟,腔/波导量子电动力学,拓扑量子光学和开放拓扑系统等方面;同时也在探索拓扑量子态在量子计算和量子技术方面的应用,提出了基于拓扑态的量子相干保护方案以及拓扑光子探测器。