Hyperfine splitting of the dressed hydrogen atom ground state in non-relativistic QED

TL;DR

This paper investigates how the interaction between electron and nucleus spins with the quantized electromagnetic field in non-relativistic QED causes hyperfine splitting of the hydrogen atom's ground state, especially at small total momentum.

Contribution

It demonstrates that spin coupling with the electromagnetic field lifts the ground state degeneracy in the non-relativistic QED model for small total momentum.

Findings

Ground state degeneracy is split by spin-field interaction.

The analysis applies to fixed small total momentum.

The study advances understanding of hyperfine structure in quantum electrodynamics.

Abstract

We consider a spin-1/2 electron and a spin-1/2 nucleus interacting with the quantized electromagnetic field in the standard model of non-relativistic QED. For a fixed total momentum sufficiently small, we study the multiplicity of the ground state of the reduced Hamiltonian. We prove that the coupling between the spins of the charged particles and the electromagnetic field splits the degeneracy of the ground state.