Bose-Einstein Condensation of Erbium

TL;DR

This paper reports the creation of Bose-Einstein condensates of erbium atoms, observes multiple Feshbach resonances at low magnetic fields, and demonstrates control over dipolar interactions leading to a d-wave collapse.

Contribution

It presents the first realization of erbium BEC, detailed Feshbach resonance spectroscopy, and the manipulation of dipolar interactions at low magnetic fields.

Findings

Achieved Bose-Einstein condensation of $^{168}$Er with up to 7×10^4 atoms.

Identified six Feshbach resonances within 3 G magnetic field range.

Demonstrated tunable dipolar BEC and observed d-wave collapse.

Abstract

We report on the achievement of Bose-Einstein condensation of erbium atoms and on the observation of magnetic Feshbach resonances at low magnetic field. By means of evaporative cooling in an optical dipole trap, we produce pure condensates of $^{168}$Er, containing up to $7 \times 10^{4}$ atoms. Feshbach spectroscopy reveals an extraordinary rich loss spectrum with six loss resonances already in a narrow magnetic-field range up to 3 G. Finally, we demonstrate the application of a low-field Feshbach resonance to produce a tunable dipolar Bose-Einstein condensate and we observe its characteristic d-wave collapse.