Theory Seminar: Unraveling Superradiance: Semiclassical Nature and Spontaneous Spin Ordering

Dr. Xin Zhang
TUM
Theory Seminar at the Lecture Hall / Herbert-Walther Hörsaal, MPQ 
Wednesday January 14th, 11:30 CET

Superradiance stands as a hallmark phenomenon in collective quantum optics. I will show the unraveling of superradiant dynamics into individual quantum trajectories via homodyne detection. Remarkably, despite the presence of entanglement, these trajectories can be effectively treated as product states for describing local observables. This finding drastically simplies the complexity of superradiant phenomona and can lead to fully classcial and exact description in some scenerios, offering both analytical treatment and intuitive understanding. Furthermore, I will show that our approach extends to regimes dominated by subradiant decay. Finally, I will present a novel emergent collective behavior in waveguide QED uncovered by this trajectory-based perspective, which renders superradiance robust to strong disorders.