A generalized G-function for the Quantum Rabi Model


Corresponding author E-mail: daniel.braak@physik.uni-augsburg.de


The analytical solution of the quantum Rabi model is based on a transcendental function math formula, the zeros of which determine the eigenenergies. math formula is generalized here to a function math formula, which allows a much better numerical control of the high-energy part of the spectrum by an appropriate choice of the complex parameter z. Additionally, it is shown that all zeros of math formula correspond to eigenvalues of the Hamiltonian as well as the zeros of math formula for imaginary z.