RF dressed atoms beyond the linear Zeeman effect

TL;DR

This paper investigates how nonlinear Zeeman shifts influence RF dressed atom traps in atom-chip setups, revealing effects that alter trap frequencies and could impact future tightly confined atom traps.

Contribution

It demonstrates the significance of nonlinear Zeeman effects on RF dressed traps, showing how they modify trap frequencies and can lead to stronger or weaker confinement.

Findings

Vibrational frequency depends on RF frequency and Landé factor sign.

Nonlinear Zeeman shifts can enhance or weaken trap confinement.

Trapping frequency on F=1 can surpass that on F=2 in 87Rb.

Abstract

We evaluate the impact that nonlinear Zeeman shifts have on resonant radio-frequency (RF) dressed traps in an atom-chip configuration. The degeneracy of the resonance between Zeeman levels is lifted at large intensities of a static field, modifying the spatial dependence of the atomic adiabatic potential. In this context, we find effects that are important for the next generation of atom chips with tight trapping: in particular, that the vibrational frequency of the atom trap is sensitive to the RF frequency and, depending on the sign of the Land\'e factor, can produce significantly weaker, or tighter trapping when compared to the linear regime of the Zeeman effect. We take 87Rb as an example and find that it is possible for the trapping frequency on F = 1 to exceed that of the F = 2 hyperfine manifold.