All-Optical Formation of Quantum Degenerate Mixtures

TL;DR

This paper demonstrates the all-optical creation of quantum degenerate mixtures of ytterbium isotopes, including Bose-Einstein condensates and a Fermi-Bose mixture, revealing collapse phenomena and stable coexistence.

Contribution

It presents the first all-optical method to produce quantum degenerate mixtures of Yb isotopes, including Bose-Einstein condensates and Fermi-Bose mixtures, with detailed observations.

Findings

Successful sympathetic cooling of 176Yb to below BEC transition temperature.

Observation of rapid atom loss indicating collapse in 176Yb condensate.

Achievement of quantum degeneracy in a 173Yb-174Yb Fermi-Bose mixture.

Abstract

We report the realization of quantum degenerate mixed gases of ytterbium (Yb) isotopes using all-optical methods. We have succeeded in cooling attractively interacting 176Yb atoms via sympathetic cooling down to below the Bose-Einstein transition temperature, coexisting with a stable condensate of 174Yb atoms with a repulsive interaction. We have observed a rapid atom loss in 176Yb atoms after cooling down below the transition temperature, which indicates the collapse of a 176Yb condensate. The sympathetic cooling technique has been applied to cool a 173Yb-174Yb Fermi-Bose mixture to the quantum degenerate regime.