On the spin–boson model with a sub–Ohmic bath

Abstract

We study the spin–boson model with a sub–Ohmic bath using infinitesimal unitary transformations. Contrary to some results reported in the literature we find a zero temperature transition from an untrapped state for small coupling to a trapped state for strong coupling. We obtain an explicit expression for the renormalized level spacing as a function of the bare papameters of the system. Furthermore we show that typical dynamical equilibrium correlation functions exhibit an algebaric decay at zero temperature. PACS codes: 71.55.-i, 05.30.Jp, 71.38.+i

Cite this paper

@inproceedings{Kehrein2008OnTS, title={On the spin–boson model with a sub–Ohmic bath}, author={Stefan K. Kehrein and Andreas Mielke}, year={2008} }