Coherent Atom-Molecule Oscillations in a Bose-Fermi Mixture

TL;DR

This paper demonstrates coherent atom-molecule superpositions in a Bose-Fermi mixture of Rb-87 and K-40, revealing oscillations that depend on magnetic fields and persist for microseconds, advancing understanding of quantum coherence in mixed systems.

Contribution

It introduces a method to create and observe coherent atom-molecule superpositions in a Bose-Fermi mixture without requiring a Bose-Einstein condensate.

Findings

Oscillations in molecule population with up to 50% contrast.

Oscillation frequencies match predicted molecule binding energies.

Superpositions persist for up to 150 microseconds.

Abstract

We create atom-molecule superpositions in a Bose-Fermi mixture of Rb-87 and K-40 atoms. The superpositions are generated by ramping an applied magnetic field near an interspecies Fano-Feshbach resonance to coherently couple atom and molecule states. Rabi- and Ramsey-type experiments show oscillations in the molecule population that persist as long as 150 microseconds and have up to 50% contrast. The frequencies of these oscillations are magnetic-field dependent and consistent with the predicted molecule binding energy. This quantum superposition involves a molecule and a pair of free particles with different statistics (i.e. bosons and fermions), and furthers exploration of atom-molecule coherence in systems without a Bose-Einstein condensate.