郭硕鸿讲座二十六（10月21日15:00）：Pseudo-Hermitian symmetry in magnon-polariton system

主持人：郭东辉 教授

报告简介：

We introduce a non-Hermitian platform allowing us to obtain a three-dimensional exceptional surface in a magnon-polariton coupled system. A two-tone driving system gives rise to a complex effective coupling, leading to a pseudo-Hermitian Hamiltonian. Independent tuning of the real and imaginary components of the coupling provides additional degrees of freedom, allowing us to form a four-dimensional parameter space in which a three-dimensional exceptional surface is proposed. We show that this pseudo-Hermitian Hamiltonian has the most general form in cavity spintronics with CPT symmetry. Our exceptional surface allows us to form a PT-like circle where the PT and anti-PT -symmetric exceptional points are unified. Moreover, we show that the CPT symmetry in our system can be reduced to PT symmetry. Our proposal makes the cavity magnon polariton a rich platform for realizing intriguing phenomena of exceptional points regardless of fabrication imperfections or exact detuning of the system frequencies.

报告人简介：

夏钶，教授，1997年南京大学物理系理学博士，1998–2002荷兰、美国等地大学物理系计算材料科学博士后。2002年入选中国科学院百人计划，2008国家杰出青年科学基金获得者。历任物理研究所副研究员、研究员，博士生导师。2009-2020年北京师范大学物理系教授，系主任，2020年-2022年北京计算科学研究研究中心教授，2022年调入东南大学物理学院。