Demonstration of a MOT in a Sub-Millimeter Membrane Hole

TL;DR

This paper reports the creation of a cold-atom ensemble within a tiny membrane hole, demonstrating a novel membrane MOT that enables efficient atom trapping and cooling in a compact, integrated platform for advanced quantum applications.

Contribution

It introduces a membrane MOT with sub-millimeter dimensions, achieving significant atom cooling and trapping, advancing integrated photonic-atom trapping technologies.

Findings

Atoms cooled to 10 μK within the membrane hole

Atom number ranges from 10^4 to 10^5

MOT cloud diameter about 180 μm

Abstract

We demonstrate the generation of a cold-atom ensemble within a sub-millimeter diameter hole in a transparent membrane, a so-called "membrane MOT". With a sub-Doppler cooling process, the atoms trapped by the membrane MOT are cooled down to 10 uK. The atom number inside the unbridged/bridged membrane hole is about 10^4 to 10^5, and the 1/e^2-diameter of the MOT cloud is about 180 um for a 400 um-diameter membrane hole. Such a membrane device can, in principle, efficiently load cold atoms into the evanescent-field optical trap generated by the suspended membrane waveguide for strong atom-light interaction and provide the capability of sufficient heat dissipation at the waveguide. This represents a key step toward the photonic atom trap integrated platform (ATIP).