How Superradiance Survives Molecular Noise inside Virus Capsids

Abstract

Excited organic dyes chemically bound to an icosahedral virus shell can spontaneously synchronize and emit a superradiant burst of light. The mechanism that allows it to occur at room temperature, despite collisional dephasing and inhomogeneous broadening, is not understood. Few other known low-dimensional condensed matter systems exhibit room-temperature superradiance (SR). In the fluctuation-prone environment of molecular-based systems, electron--vibrational coupling has been proposed to play a central role. Here, we addressed experimentally the existence of underdamped virus capsid phonon-like modes and theoretically their involvement in the transition from uncorrelated to cooperative emission. We find that SR-active dye-labeled capsids exhibit underdamped low-frequency oscillations that modulate the dye excited-state response, and modeling shows how such capsid motion can promote the collective polarization required for superradiant emission.