Generalized adiabatic approximation to the asymmetric quantum Rabi model: conical intersections and geometric phases

The asymmetric quantum Rabi model (AQRM), which describes the interaction between a harmonic oscillator and biased qubit, arises naturally in circuit electrodynamic circuits devices. existence of hidden symmetry AQRM leads to rich energy landscape conical intersections (CIs) thus interesting topological properties. However, current approximations fail reproduce these CIs correctly. To overcome limitations we propose generalized adiabatic approximation (GAA) describe spectrum AQRM. This is achieved by combining perturbative exact exceptional solutions GAA provides substantial improvement existing approaches pushes limit treatment into non-perturbative regimes. As preliminary example application calculate geometric phases around associated with