Lower Spectral Branches of a Spin-Boson Model

Abstract

We study the structure of the spectrum of a two-level quantum system weakly coupled to a boson field (spin-boson model). Our analysis allows to avoid the cutoff in the number of bosons, if their spectrum is bounded below by a positive constant. We show that, for small coupling constant, the lower part of the spectrum of the spin-boson Hamiltonian contains (one or two) isolated eigenvalues and (respectively, one or two) manifolds of atom $+1$-boson states indexed by the boson momentum $q$. The dispersion laws and generalized eigenfunctions of the latter are calculated.

References in corpus (1)

• Lower Spectral Branches of a Particle Coupled to a Bose Field

Cited by in corpus (5)

• On the spectrum of the lattice spin-boson Hamiltonian for any coupling: 1D case
• Absence of Embedded Mass Shells: Cerenkov Radiation and Quantum Friction
• Spectral analysis of the spin-boson Hamiltonian with two photons for arbitrary coupling
• Discrete eigenvalues of the spin-boson Hamiltonian with two photons: on a problem of Minlos and Spohn
• Spectral analysis of the spin-boson Hamiltonian with two bosons for arbitrary coupling and bounded dispersion relation