报告题目 ：Light propagation and magnon-photon coupling in optically dispersive 

                magnetic media 

报告人：   Prof. Silvia Viola Kusminskiy  教授 (德国亚琛工业大学, RWTH Aachen) 

报告时间：2024年5月27日（星期一）15：00-16：00

报告地点：北洋园校区 32 教 140 室 （线上：腾讯会议 838-9499-4192）

报告摘要：

       In this talk I will discuss our recent theoretical results considering a system based on a magnetized epsilon-near-zero (ENZ) medium, where we show that strong coupling between magnetic excitations (magnons) and light can be achieved close to the ENZ frequency due to a drastic enhancement of the magneto-optical response. We adopt a phenomenological approach to quantize the electromagnetic field inside a dispersive magnetic medium in order to obtain the frequency-dependent coupling between magnons and photons. We predict that, in the epsilon-near-zero regime, the single-magnon single-photon coupling can be comparable to the magnon frequency for a small magnetic volume and perfect mode overlap. For state-of-the-art illustrative values, this would correspond to achieving the single-magnon strong coupling regime, where the coupling rate is larger than all the decay rates. Moreover, we show that the coupling of magnons to plane-wave nondegenerate Voigt modes vanishes at specific frequencies due to polarization selection rules tuned by dispersion. The nonlinear energy spectrum intrinsic to this coupling regime can be probed via the characteristic multiple magnon sidebands in the photon power spectrum.

报告人简介：

      Silvia Viola Kusminskiy is currently Professor for Theoretical Condensed Matter Physics at RWTH Aachen University. After undergraduate and master studies at the Universidad de la República (University of the Republic) in Uruguay, she obtained her PhD in Physics from Boston University in the USA. She continued her academic career in Germany, where she held postdoctoral positions at the Freie Universitaet Berlin, the Friedrich-Alexander University Erlangen-Nuernberg, and at the Max Planck Institute for the Science of Light (MPL) in Erlangen, Germany. From 2018 to 2022 she lead the Max Planck Research Group “Theory of Hybrid Quantum Systems” at MPL. Her research comprises mesoscopic systems and light-matter interaction, with emphasis on collective phenomena and a focus on hybrid quantum systems including magnetic degrees of freedom. 

参考文献：

[1] V. A. S. V. Bittencourt, I. Liberal, and S. Viola Kusminskiy, Phys. Rev. Lett. 128, 183603 (2022).

[2] V. A. S. V. Bittencourt, I. Liberal, and S. Viola Kusminskiy, Phys. Rev. B 105, 014409 (2022).