Accuracy of second order perturbation theory in the polaron and variational polaron frames
Accuracy of second order perturbation theory in the polaron and variational polaron frames
In the study of open quantum systems, the polaron transformation has recently attracted a renewed interest as it offers the possibility to explore the strong system-bath coupling regime. Despite this interest, a clear and unambiguous analysis of the regimes of validity of the polaron transformation is still lacking. Here we …