On the spin-boson model with a sub-ohmic bath

被引：98

作者：

Kehrein, SK

Mielke, A

机构：

[1] Inst. für Theoretische Physik, Ruprecht-Karls-Universität, D-69120 Heidelberg

来源：

PHYSICS LETTERS A | 1996年 / 219卷 / 5-6期

关键词：

quantum dissipative systems; spin-boson model; sub-ohmic bath; flow equations;

D O I：

10.1016/0375-9601(96)00475-6

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

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 parameters of the system. Furthermore we show that typical dynamical equilibrium correlation functions exhibit an algebraic decay at zero temperature.

引用

页码：313 / 318

页数：6