| Time：1150422 (Wed.) 14:20~16:20 Speaker：Dr. 林冠廷(LIN, Kuan-Ting) 鴻海研究院離子阱實驗室/Trapped-Ion Quantum Computing Laboratory, Hona Hai Research Institute Title：Beyond Population Inversion: Microwave Amplification via Dressed-State Interference in Waveguide QED Systems Abstract： Realizing efficient gain elements at the single-atom level is a fundamental challenge in quantum technologies, primarily due to the spatial mode mismatch inherent in three-dimensional free space. Waveguide quantum electrodynamics (QED) solves this problem by confining electromagnetic fields to one dimension, thereby resulting in strong light-matter interactions. In this work, we investigate microwave amplification utilizing a single, multi-level transmon artificial atom coupled to a semi-infnite transmission line. When subjected to an intense pump field, the anharmonic transmon exhibits multi-photon excitations, leading to the formation of a complex dressed-state structure. Moving beyond the paradigm of population inversion, our results demonstrate that amplification can be dominantly induced by the constructive quantum interference between nearly degenerate Rabi sidebands. Place：S101, Gongguan Campus, NTNU |
