Total control over ultracold interactions via electric and magnetic fields

TL;DR

This paper demonstrates that combining electric and magnetic fields allows independent tuning of both the scattering length and effective range in ultracold atomic interactions, enabling complete control over elastic collisions.

Contribution

It introduces a method to independently manipulate both the scattering length and effective range using combined electric and magnetic fields, surpassing previous magnetic-only control.

Findings

Independent control over scattering length and effective range achieved

Full tunability of ultracold elastic interactions demonstrated

Potential applications in quantum simulation and control

Abstract

The scattering length is commonly used to characterize the strength of ultracold atomic interactions, since it is the leading parameter in the low-energy expansion of the scattering phase shift. Its value can be modified via a magnetic field, by using a Feshbach resonance. However, the effective range term, which is the second parameter in the phase shift expansion, determines the width of the resonance and gives rise to important properties of ultracold gases. Independent control over this parameter is not possible by using a magnetic field only. We demonstrate that a combination of magnetic and electric fields can be used to get independent control over both parameters, which leads to full control over elastic ultracold interactions.