Oscillator bath simulation of the spin bath (1703.04592v6)

Abstract: Open quantum systems are subject to interaction with their surrounding environment. In many applications, at low temperatures, quantum environments fall into two universality classes of models: Caldeira-Leggett oscillator bath models and Prokof'ev-Stamp spin bath models. The two classes are commonly recognized to be distinct and to have strikingly different effects on principal systems, except at weak coupling limits. However, I show here, in contrast, that oscillator bath models can simulate the effect of spin bath models in strong coupling limit of the spin bath. I choose parameters of the oscillator bath models such that they produce incoherent relaxation, just as in the spin bath models, with relaxation rates for a two-state system (a qubit) equivalent to those of the spin bath models in the strong coupling limit.