Magnetic trapping of silver and copper, and anomolous spin relaxation in the Ag-He system

TL;DR

This study demonstrates the successful magnetic trapping of copper and silver atoms with long lifetimes and high elastic-to-inelastic collision ratios, revealing anomalous spin relaxation behavior in the Ag-He system.

Contribution

It reports the first large-scale trapping of copper and silver atoms using buffer gas cooling and uncovers unexpected collisional dynamics in the Ag-He system.

Findings

Copper and silver atoms trapped up to 3x10^12 and 4x10^13 respectively.

Lifetimes of trapped atoms up to 5 seconds.

Elastic to inelastic collision ratios exceed 10^6.

Abstract

We have trapped large numbers of copper and silver atoms using buffer gas cooling. Up to 3x10^12 copper atoms and 4x10^13 silver atoms are trapped. Lifetimes are as long as 5 s, limited by collisions with the buffer gas. Ratios of elastic to inelastic collision rates with He are >~ 10^6, suggesting copper and silver are favorable for use in ultracold applications. The temperature dependence of the silver-helium-3 collision rate varies as T^5.8. We find that this temperature dependence is inconsistent with the behavior predicted for relaxation arising from the spin-rotation interaction, and conclude that the silver-helium-3 system displays anomalous collisional behavior in the multiple-partial wave regime. Lifetimes of laser ablated gold in helium-3 buffer gas are too short to permit trapping.