Theory of Acoustic-Phonon-Induced Dephasing in GaN Defect Emitters

Defect-based quantum emitters in gallium nitride (GaN) have recently emerged as highly promising quantum light sources for quantum information technologies. Dephasing processes lead to the broadening of the photoluminescence (PL) linewidth, thereby limiting photon indistinguishability. Experimental studies of GaN defect emitters integrated with solid immersion lenses have revealed a clear temperature dependence of both the PL linewidth and lineshape. In this paper, we present a rigorously derived theoretical model that explains the temperature-dependent evolution of the PL linewidth and lineshape. This theoretical framework is not only applicable to GaN, but is also instructive for defect emitters in other wide-bandgap solid-state materials.