Stand-alone vacuum cell for compact ultracold quantum technologies

TL;DR

This paper introduces a compact, passive vacuum cell for ultracold quantum technologies that maintains ultra-high vacuum conditions over long periods, enabling portable and reliable cold atom devices with minimal power and maintenance.

Contribution

The authors present a novel, small-scale ceramic vacuum chamber with integrated optics and passive pumping, achieving long-term stable ultrahigh vacuum suitable for portable quantum sensors.

Findings

Achieved $10^7$ laser-cooled $^{87}$Rb atoms per second.

Demonstrated vacuum stability over more than 500 days with passive pumping.

Estimated vacuum lifetime of several years based on helium throughput.

Abstract

Compact vacuum systems are key enabling components for cold atom technologies, facilitating extremely accurate sensing applications. There has been important progress towards a truly portable compact vacuum system, however size, weight and power consumption can be prohibitively large, optical access may be limited, and active pumping is often required. Here, we present a centilitre-scale ceramic vacuum chamber with He-impermeable viewports and an integrated diffractive optic, enabling robust laser cooling with light from a single polarization-maintaining fibre. A cold atom demonstrator based on the vacuum cell delivers $10^7$ laser-cooled $^{87}$Rb atoms per second, using minimal electrical power. With continuous Rb gas emission active pumping yields a $10^{-7}\,$mbar equilibrium pressure, and passive pumping stabilises to $3\times 10^{-6}\,$mbar, with a $17\,$day time constant. A vacuum cell, with no Rb dispensing and only passive pumping, has currently kept a similar pressure for more than \ch{500 days}. The passive-pumping vacuum lifetime is several years, estimated from short-term He throughput, with many foreseeable improvements. This technology enables wide-ranging mobilization of ultracold quantum metrology.