Feshbach Resonances in an Erbium-Dysprosium Dipolar Mixture

TL;DR

This paper reports the observation and characterization of heteronuclear Feshbach resonances in erbium-dysprosium mixtures, highlighting broad resonances useful for tuning interactions in dipolar quantum gases.

Contribution

It provides the first detailed observation of heteronuclear Feshbach resonances in Er-Dy mixtures, including characterization of broad resonances and their potential for controlling interspecies interactions.

Findings

Identification of two broad Feshbach resonances (>1 G width)

Temperature-dependent loss rates indicating universal scaling

Increased density of narrow resonances in mixtures

Abstract

We report on the observation of heteronuclear magnetic Feshbach resonances in several isotope mixtures of the highly magnetic elements erbium and dysprosium. Among many narrow features, we identify two resonances with a width greater than one Gauss. We characterize one of these resonances, in a mixture of $^{168}$Er and $^{164}$Dy, in terms of loss rates and elastic cross section, and observe a temperature dependence of the on-resonance loss rate suggestive of a universal scaling associated with broad resonances. Our observations hold promise for the use of such a resonance for tuning the interspecies scattering properties in a dipolar mixture. We further compare the prevalence of narrow resonances in an $^{168}$Er-$^{164}$Dy mixture to the single-species case, and observe an increased density of resonances in the mixture.