📝 SummarXiv

Abstract

Superfluorescence, a cooperative emission phenomenon arising from the coherent coupling of excited dipoles, has historically been observed under optical excitation in carefully engineered quantum systems. Here, we report the first observation of superfluorescence triggered by ionizing radiation in lead-halide perovskite nanocrystal (NC) superlattices. Using CsPbBr3 NC superlattices with long-range structural and electronic order, we demonstrate that secondary electrons generated by high-energy photons can induce efficient cooperative emission bursts characteristic of superfluorescence with unprecedented scintillation lifetime of ~40 ps, thereby introducing a new class of coherent scintillating metamaterials. Side-by-side optical and scintillation measurements reveal a direct analogy between ionizing and intense optical excitation, both leading to high excitonic densities that result in superfluorescent emission, even at mild, technologically accessible cryogenic temperatures. The discovery that incoherent, stochastic ionization cascades can seed coherent many-body optical responses with radiatively accelerated luminescence and large Stokes shifts establishes a pathway toward ultrafast, reabsorption-free, quantum-ordered nanotechnological scintillators, paving the way for the future development of radiation detectors based on quantum technologies for advanced radiation detection applications.