Level Splitting in Association with the Multiphoton Bloch-Siegert Shift

TL;DR

This paper introduces a unitary equivalent spin-boson Hamiltonian to analyze the Bloch-Siegert shift and associated level splittings, using perturbation theory for moderate coupling scenarios.

Contribution

It provides a novel Hamiltonian formulation that isolates contributions to the Bloch-Siegert shift and level splittings, advancing understanding of resonance phenomena.

Findings

Identification of Hamiltonian terms contributing to the Bloch-Siegert shift

Approximate level splitting results using perturbation theory

Analysis applicable to moderate coupling regimes

Abstract

We present a unitary equivalent spin-boson Hamiltonian in which terms can be identified which contribute to the Bloch-Siegert shift, and to the level splittings at the anticrossings associated with the Bloch-Siegert resonances. First-order degenerate perturbation theory is used to develop approximate results in the case of moderate coupling for the level splitting.