Observation of Heteronuclear Feshbach Resonances in a Bose-Fermi Mixture

TL;DR

This paper reports the discovery of three heteronuclear Feshbach resonances in a Bose-Fermi mixture of 87Rb and 40K, providing crucial data for controlling interspecies interactions in quantum gases.

Contribution

The study identifies specific heteronuclear Feshbach resonances and measures their properties, offering new insights for manipulating Bose-Fermi mixtures.

Findings

Identified three Feshbach resonances at 492, 512, and 543 G.

Measured scattering lengths: -281 and -54 Bohr.

Observed a broad resonance at 543 G with a width of 3.7 G.

Abstract

Three magnetic-field induced heteronuclear Feshbach resonances were identified in collisions between bosonic 87Rb and fermionic 40K atoms in their absolute ground states. Strong inelastic loss from an optically trapped mixture was observed at the resonance positions of 492, 512, and 543 +/- 2 G. The magnetic-field locations of these resonances place a tight constraint on the triplet and singlet cross-species scattering lengths, yielding -281 +/- 15 Bohr and -54 +/- 12 Bohr, respectively. The width of the loss feature at 543 G is 3.7 +/- 1.5 G wide; this broad Feshbach resonance should enable experimental control of the interspecies interactions.