Short-time emission of higher-angular-momentum photons by atomic transitions

Abstract

The short-time regime of spontaneous light emission by few-electron ions is examined in detail, with a specific emphasis on the angular momentum of the emitted light. It is found that, in general, photons carrying a higher angular momentum are emitted with important probabilities, at short times, in transitions that are not of the electric dipole type. The probability of emission of such photons is found to be parametrically non-negligible in this time regime, and even numerically dominant for some cases. It is also found that, in all time regimes, the emission of electric 2 n+1-pole fields is typically numerically dominant over the emission of magnetic 2 n -pole fields by many orders of magnitude. These results refine and deepen our understanding of the emission of angular momentum-carrying light by simple atomic systems.