TY - JOUR
T1 - Spin-boson type models analyzed using symmetries
AU - Dam, Thomas Norman
AU - Møller, Jacob Schach
N1 - Publisher Copyright:
© 2020 by Kyoto University
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/12
Y1 - 2020/12
N2 - We analyze a family of models for a qubit interacting with a bosonic field. This family of models is very large and contains models where higher-order perturbations of field operators are added to the Hamiltonian. The Hamiltonian has a special symmetry, called spin-parity symmetry, which plays a central role in our analysis. Using this symmetry, we find the domain of self-adjointness and we decompose the Hamiltonian into two fiber operators each defined on Fock space. We then prove the Hunziker-van Winter-Zhislin (HVZ) theorem for the fiber operators, and we single out a particular fiber operator which has a ground state if and only if the full Hamiltonian has a ground state. From these results, we deduce a simple criterion for the existence of an excited state.
AB - We analyze a family of models for a qubit interacting with a bosonic field. This family of models is very large and contains models where higher-order perturbations of field operators are added to the Hamiltonian. The Hamiltonian has a special symmetry, called spin-parity symmetry, which plays a central role in our analysis. Using this symmetry, we find the domain of self-adjointness and we decompose the Hamiltonian into two fiber operators each defined on Fock space. We then prove the Hunziker-van Winter-Zhislin (HVZ) theorem for the fiber operators, and we single out a particular fiber operator which has a ground state if and only if the full Hamiltonian has a ground state. From these results, we deduce a simple criterion for the existence of an excited state.
UR - http://www.scopus.com/inward/record.url?scp=85097661104&partnerID=8YFLogxK
U2 - 10.1215/21562261-2019-0062
DO - 10.1215/21562261-2019-0062
M3 - Journal article
AN - SCOPUS:85097661104
SN - 2156-2261
VL - 60
SP - 1261
EP - 1332
JO - Kyoto Journal of Mathematics
JF - Kyoto Journal of Mathematics
IS - 4
ER -