Superfluorescence in lead halide perovskites is a light induced phase transition: an evidence for criticality

Lead halide perovskites have been recently shown to exhibit superfluorescence (SF) at high temperatures. This has made them attractive platforms for developing future technologies, offering immense potential for room temperature innovations in quantum computing, quantum control, etc. As a radiation-collective phenomenon, the emergence of SF from the incoherent photoluminescence (PL) emission, as a result of ultrafast short pulse laser excitation, is very dependent on the power excitation density and temperature. The realization of this superradiant phase transition suggests an underlying dynamic order undergoing in the crystal with symmetry-breaking properties. Those properties can be accessed optically via the PL spectra and studied phenomenologically as a function of temperature. In this poster presentation, I will talk about our recent temperature-dependent studies of steady-state and time-resolved PL experiments in relation to the superradiant phase transition in quasi 2D PEA:CsPbBr3 thin films. Our studies near phase transition temperature together with the analysis of the power laws evidence criticality and universality class for perovskite superradiant phase transition.