Enhancing fiber atom interferometer by in-fiber laser cooling

TL;DR

This paper reports a significant extension of fiber-guided atom interferometer coherence time by implementing in-fiber laser cooling techniques, enabling more precise inertial sensing in compact quantum sensors.

Contribution

It introduces in-fiber laser cooling methods to prolong atom interferometer coherence time inside a hollow-core fiber, a novel approach for compact quantum sensing.

Findings

Interferometer time extended to 20 ms, three orders longer than previous.

Achieved cooling of atoms from 32 μK to below 1 μK in 4 ms.

Potential for sub-millimeter resolution in compact inertial sensors.

Abstract

We demonstrate an inertia sensitive atom interferometer optically guided inside a 22-cm-long negative curvature hollow-core photonic crystal fiber with an interferometer time of 20 ms. The result prolongs the previous fiber guided atom interferometer time by three orders of magnitude. The improvement arises from the realization of in-fiber {\Lambda}-enhanced gray molasses and delta-kick cooling to cool atoms from 32 {\mu}K to below 1 {\mu}K in 4 ms. The in-fiber cooling overcomes the inevitable heating during the atom loading process and allows a shallow guiding optical potential to minimize decoherence. Our results permit bringing atoms close to source fields for sensing and could lead to compact inertial quantum sensors with a sub-millimeter resolution.