Copenhagen University
报告人简介
Dr. Xiang Xi is an Assistant Professor in the Quantum Optics Section at the Niels Bohr Institute, University of Copenhagen. He received his bachelor’s degree from Huazhong University of Science and Technology in 2015 and his Ph.D. from the Chinese University of Hong Kong in 2021. His doctoral research focused on optical forces, integrated topological photonics and nanomechanics. Following his Ph.D., Dr. Xi joined the group of Prof. Albert Schliesser at the Niels Bohr Institute as a postdoctoral researcher in 2022 and has been serving as an Assistant Professor since 2024. His current research explores quantum opto- and electromechanical systems as well as topological mechanics. Dr. Xi is a recipient of the Marie Skłodowska-Curie Postdoctoral Fellowship (2023) and the Villum Experiment Grant (2024).
报告摘要
dissipation-diluted and soft-clamped thin membranes exhibit extremely low mechanical loss, achieving coherent lifetimes exceeding 100 ms. This remarkable property makes them excellent platforms for exploring macroscopic quantum phenomena and new physics. In this talk, I will present my recent exploration of ultralow loss phononic devices with quantum and topological systems. First, I will discuss our progress in developing quantum transducers between microwaves and optical photons by coupling phononic resonators to superconducting microwave circuits and infrared optical modes. Such transducers are key components for interconnecting remote quantum systems and enabling a future quantum internet. Second, I will present our recent results on realizing ultralow loss topological phononic waveguides with propagation losses as low as 3 dB/km, a key block for phononic circuitry. This exceptionally low loss allows precise quantification of backscattering immunity, demonstrating suppression down to 1×10-4 across a 120° sharp bend. Our results are promising for the development of future ultracoherent phononic circuits, enabling new applications and providing a powerful platform for exploring fundamental physics.
报告地点：中国科学院物理研究所中关村M楼253会议室
邀请人：李贝贝 研究员
联系人：孙丽（18601300418）
主办单位：中国科学院物理研究所应用物理中心