Dissipative Equation of Motion for Electromagnetic Radiation in Quantum Dynamics

BUSTAMANTE, CARLOS M.; GADEA, ESTEBAN D.; HORSFIELD, ANDREW; TODOROV, TCHAVDAR N.; GONZÁLEZ LEBRERO, MARIANO C.; SCHERLIS, DAMIÁN A.

PHYSICAL REVIEW LETTERS

AMER PHYSICAL SOC

Lugar: New York; Año: 2021 vol. 126

0031-9007

The dynamical description of the radiative decay of an electronically excited state in realistic many-particle systems is an unresolved challenge. In the present investigation electromagnetic radiation of the charge density is approximated as the power dissipated by a classical dipole, to cast the emission in closed form as a unitary single-electron theory. This results in a formalism of unprecedented efficiency, critical for ab initio modeling, which exhibits at the same time remarkable properties: it quantitatively predicts decay rates, natural broadening, and absorption intensities. Exquisitely accurate excitation lifetimes are obtained from time-dependent DFT simulations for C2þ, Bþ, and Be, of 0.565, 0.831, and 1.97 ns, respectively, in accord with experimental values of 0.57 0.02, 0.86 0.07, and 1.77?2.5 ns. Hence, the present development expands the frontiers of quantum dynamics, bringing within reach first-principles simulations of a wealth of photophysical phenomena, from fluorescence to time-resolved spectroscopies.