A master equation for high-precision spectroscopy

Andreas Alexander Buchheit, Giovanna Morigi

Published 2015-11-11Version 1

The progress in high-precision spectroscopy requires one to check the accuracy of theoretical models such as the master equation describing spontaneous emission of atoms. For this purpose, we systematically derive a master equation of an atom interacting with the modes of the electromagnetic field which naturally includes interference in the decay channels and fulfills the requirements of the Lindblad theorem without the need of phenomenological assumptions. We apply our model to the 2S-4P transition in atomic Hydrogen and show that interference effects in the dissipative dynamics can alter the lineshape of the spectroscopic line, leading to frequency shifts ranging from few to tens of kHz, depending on the collection angle of the photodetection setup. These results can contribute in understanding spectroscopic measurements in atomic Hydrogen performed in recent experiments for testing the validity of quantum electrodynamics.