An ultracold, optically trapped mixture of {87}Rb and metastable {4}He atoms

TL;DR

This paper demonstrates the creation of an ultracold mixture of rubidium and metastable helium atoms in an optical trap, highlighting long trapping lifetimes for certain spin states and discussing future quantum degeneracy applications.

Contribution

The study introduces a novel method for trapping and cooling a mixture of {87}Rb and metastable {4}He atoms in an optical dipole trap, with detailed lifetime measurements.

Findings

Long trapping lifetimes for spin-stretched states

Shorter lifetimes for other spin states

Potential for quantum degenerate mixtures

Abstract

We report on the realization of an ultracold (<25~muK) mixture of rubidium ({87}Rb) and metastable triplet helium ({4}He) in an optical dipole trap. Our scheme involves laser cooling in a dual-species magneto-optical trap, simultaneous MW- and RF-induced forced evaporative cooling in a quadrupole magnetic trap, and transfer to a single-beam optical dipole trap. We observe long trapping lifetimes for the doubly spin-stretched spin-state mixture and measure much shorter lifetimes for other spin-state combinations. We discuss prospects for realizing quantum degenerate mixtures of alkali-metal and metastable helium atoms.