Toward a measurement of the effective gauge field and the Born-Huang potential with atoms in chip traps

TL;DR

This paper investigates the breakdown of the Born-Oppenheimer approximation in high-frequency magnetic atom traps, revealing how effective gauge fields emerge from non-adiabatic dynamics through exact numerical analysis.

Contribution

It provides a detailed numerical study of non-adiabatic effects and effective fields in atom chip traps, advancing understanding of atom-field interactions beyond the adiabatic approximation.

Findings

Identification of non-adiabatic effects on trap states

Calculation of effective gauge fields and Born-Huang potential

Analysis of trap state decay rates and energy shifts

Abstract

We study magnetic traps with very high trap frequencies where the spin is coupled to the motion of the atom. This allows us to investigate how the Born-Oppenheimer approximation fails and how effective magnetic and electric fields appear as the consequence of the non-adiabatic dynamics. The results are based on exact numerical diagonalization of the full Hamiltonian describing the coupling between the internal and external degrees of freedom. The position in energy and the decay rate of the trapping states correspond to the imaginary part of the resonances of this Hamiltonian and are computed using the complex rotation method.