An atom chip interferometer

TL;DR

This paper reports the realization of a chip-based atom interferometer using thermal rubidium atoms, demonstrating spatial splitting, interference fringes, and a model for contrast decay.

Contribution

It introduces a novel chip-integrated atom interferometer with on-chip microwave splitting and models the contrast decay due to velocity differences.

Findings

Maximum atom separation of 1.2 micrometers achieved.

Interference fringes observed with 8% contrast.

Contrast decay modeled based on velocity differences.

Abstract

We have realized an interferometer using a thermal cloud of magnetically trapped rubidium 87 atoms on a chip. The interferometer resembles a Ramsey interferometer with a state selective spatial splitting of the two internal states as proposed in [M. Ammar, and al., Phys. Rev. A, 91, 053623]. The splitting is effected by microwave fields from two on-chip waveguides while the atoms remain magnetically trapped. The inferred maximum separation is $1.2\pm 0.1~\mu$m. We observe interference fringes with a contrast around 8\% limited by velocity difference of the two interferometer states when we close the interferometer. We develop a model describing this contrast decay.