Quantum integrability and nonintegrability in the spin-boson model

Vyacheslav V. Stepanov, Gerhard Muller, Joachim Stolze

We study the spectral properties of a spin-boson Hamiltonian that depends on two continuous parameters $0\le \Lambda <\infty$ (interaction strength) and $0\le \alpha \le \pi /2$ (integrability swi…