學術活動
凝聚态
【凝聚态物理-beat365論壇 2025年第3期(總614期)】From Polaritons to Lasing via Exceptional Points
浏覽次數:
主講人: Prof.Jacob Khurgin(約翰霍普金斯大學)
地點: 物理樓西202報告廳
時間: 2025年3月6日(星期四) 下午3:00-4:30
主持 聯系人: 馬仁敏 renminma@pku.edu.cn
主講人簡介: Jacob Khurgin, a professor of electrical and computer engineering at Johns Hopkins University, is known for his diverse and eclectic research in the areas of optics, electronics, condensed matter physics, and telecommunications. He has published eight book chapters, 40 patents, 340 papers in refereed journals. The insights that have emerged from his research have led to numerous inventions ranging from small appliances, such as electric shavers and coffeemakers, to sophisticated systems for laser communication and chemical detection. He is a member of the American Physical Society Joint Council on Quantum Electronics and has served as a technical program committee member for more than 60 academic conferences. He has held visiting professorships at numerous institutions, including Princeton, UCLA, Brown, ETH in Zurich, and Ecole Normale Superieure in Paris. He was named a Fellow by the American Physical Society and the Optical Society of America.

   Recent interest in non-Hermitian quantum mechanics stems from the discovery of exceptional points (EPs), which mark the transition between regions of preserved and broken parity-time (PT) symmetry, where Hamiltonian eigenfunctions become degenerate. In photonics, PT symmetry arises from non-Hermiticity, represented by gain and loss. In the first part of this talk I show that eigenmodes of active, pumped cavity polaritons with population inversion exhibit features resembling PT symmetry. In the second part of the talk, I consider in depth the possibility of realizing asymmetric mode switching and omni-polarizer action through the dynamic encirclement of Eps and offer a new perspective on the operating principle of these devices. The experimentally confirmed proposed concept of “encirclement emulators” may allow a better assessment of the limitations, practical potential, and applications of EP encirclements in non-Hermitian photonics.