Long spatial coherence times a few micro-meters from a room temperature surface

TL;DR

This paper demonstrates the trapping and sustained spatial coherence of Bose-Einstein Condensates just 5 micrometers from a room temperature surface, advancing atomchip technology for quantum applications.

Contribution

It reports the first achievement of maintaining spatial coherence of atoms at a significantly reduced distance from a room temperature surface, enabling atomic circuits and exploring maximal dephasing regimes.

Findings

Achieved spatial coherence of BECs at 5μm from a room temperature surface

Reduced atom-surface distance compared to previous experiments

Explored the regime of maximal spatial dephasing

Abstract

The search for quantum coherence based on isolated atoms integrated with a room temperature solid state device (so-called atomchip [1-3]) has been intensifying in the last decade, with advances being made towards applications such as clocks, quantum information processing, surface probing and acceleration and gravitational field sensors. Such a device will also enable (and to some extent has already enabled) novel experiments in fundamental physics (e.g., [4-7]). Here we report on the trapping and maintenance of spatial coherence of atoms (in a Bose-Einstein Condensate -- BEC) about 5$\mu$m from a room temperature surface, reducing significantly the distance previously achieved between the spatially coherent atoms and their classical environment [8-12], and most importantly entering the regime where atomic circuits are enabled. In addition, we enter the interesting regime in which the distance to the surface is much smaller than the probed coherence length, a regime in which the spatial dephasing reaches its maximal rate.