Generalized rotating-wave approximation for arbitrarily large coupling

TL;DR

This paper introduces a generalized rotating-wave approximation that improves accuracy for the spin-boson Hamiltonian across all coupling strengths and detuning values, enhancing modeling in solid-state physics.

Contribution

It presents a simple basis change method that extends the rotating-wave approximation's applicability to arbitrarily large coupling regimes.

Findings

More accurate energy level calculations across coupling strengths

Applicable to a wide range of detuning values

Potential use in solid-state experimental analysis

Abstract

A generalized version of the rotating-wave approximation for the single-mode spin-boson Hamiltonian is presented. It is shown that performing a simple change of basis prior to eliminating the off-resonant terms results in a significantly more accurate expression for the energy levels of the system. The generalized approximation works for all values of the coupling strength and for a wide range of detuning values, and may find applications in solid-state experiments.