Towards surface quantum optics with Bose-Einstein condensates in evanescent waves

TL;DR

This paper introduces a novel surface trap combining magnetic and evanescent wave potentials, enabling controlled positioning of Bose-Einstein condensates near surfaces for quantum optics studies.

Contribution

It presents a new surface trap design that allows precise control of ultracold atoms close to surfaces, facilitating surface quantum optics experiments.

Findings

Stable positioning of Rb BECs below one micrometer from surfaces.

Effective compensation of van der Waals forces by evanescent wave potential.

High-precision control of atom-surface distance.

Abstract

We present a surface trap which allows for studying the coherent interaction of ultracold atoms with evanescent waves. The trap combines a magnetic Joffe trap with a repulsive evanescent dipole potential. The position of the magnetic trap can be controlled with high precision which makes it possible to move ultracold atoms to the surface of a glass prism in a controlled way. The optical potential of the evanescent wave compensates for the strong attractive van der Waals forces and generates a potential barrier at only a few hundred nanometers from the surface. The trap is tested with Rb Bose-Einstein condensates (BEC), which are stably positioned at distances from the surfaces below one micrometer.