A toroidal trap for cold $^{87}Rb$ atoms using an rf-dressed quadrupole trap

TL;DR

This paper demonstrates a method to trap cold rubidium-87 atoms in a toroidal shape using an rf-dressed quadrupole magnetic trap, enabling adjustable ring radii and potential applications in quantum sensing.

Contribution

The authors introduce a novel rf-dressed quadrupole trap for creating a tunable toroidal atom trap using a single rf source and antenna.

Findings

Successful creation of a toroidal trap with variable radius

Use of a single rf source for both cooling and dressing

Potential applications in atom gyroscopes and low-dimensional quantum gases

Abstract

We demonstrate the trapping of cold $^{87}Rb$ atoms in a toroidal geometry using a radio frequency (rf) dressed quadrupole magnetic trap formed by superposing a strong rf-field on a quadrupole trap. This rf-dressed quadrupole trap has the minimum potential away from the quadrupole trap centre on a circular path which facilitates trapping in toroidal geometry. In these experiments, the laser cooled atoms were first trapped in a quadrupole trap, then cooled evaporatively using a weak rf-field, and finally trapped in an rf-dressed quadrupole trap. The radius of the toroid could be varied by varying the frequency of the dressing rf-field. It has also been demonstrated that a single rf source and an antenna can be used for the rf-evaporative cooling as well as for the rf-dressing of atoms. The atoms trapped in the toroidal trap may have applications in the realization of an atom gyroscope as well as in studying the quantum gases in low dimensions.