Robust spatial coherence 5$\,\mu$m from a room-temperature atom chip

TL;DR

This study demonstrates that Bose-Einstein condensates maintain spatial coherence over multiple lattice sites at room temperature and very close to a surface, which is promising for atomic circuits and understanding coherence dynamics.

Contribution

It provides experimental evidence of long-lasting spatial coherence of BECs near room-temperature surfaces at micrometer scales, advancing potential applications in atomic circuitry.

Findings

Spatial coherence persists for ≥500 ms near a surface

Coherence extends over multiple lattice sites

Coherence is maintained at 5 μm from a room-temperature surface

Abstract

We study spatial coherence near a classical environment by loading a Bose-Einstein condensate into a magnetic lattice potential and observing diffraction. Even very close to a surface (5$\,\mu$m), and even when the surface is at room temperature, spatial coherence persists for a relatively long time ($\ge$500$\,$ms). In addition, the observed spatial coherence extends over several lattice sites, a significantly greater distance than the atom-surface separation. This opens the door for atomic circuits, and may help elucidate the interplay between spatial dephasing, inter-atomic interactions, and external noise.