Title: Rethinking Superfluorescence: A Window into Macroscopic Quantum Order

Abstract: Macroscopic quantum coherence is typically associated with low temperatures, where thermal fluctuations do not rapidly destroy phase correlations. In solids, however, electronic coherence is strongly influenced by lattice dynamics, making it unclear how collective quantum states can persist at elevated temperatures. 

In this talk, I will show how studies of superfluorescence provide a powerful window into the emergence of macroscopic coherence in condensed matter systems. By tracking the buildup of collective emission in lead-halide perovskites, we find that superfluorescence does not originate from simple radiative synchronization of independent dipoles. Instead, it reflects the formation of an underlying many-body excitonic state, shaped by strong exciton–lattice interactions. Our results reveal a general mechanism in which lattice dynamics actively reorganize the electronic landscape, enabling the emergence of coherent excitonic order at high temperatures. This perspective establishes superfluorescence as a diagnostic of nonequilibrium phase transitions and points to a broader principle for achieving macroscopic quantum coherence in strongly interacting systems.