A strongly interacting gas of two-electron fermions at an orbital Feshbach resonance

TL;DR

This paper reports the experimental creation of a strongly interacting ultracold two-electron fermion gas with orbital degrees of freedom, achieved via a novel Feshbach resonance in 173Yb atoms, enabling exploration of new quantum states.

Contribution

Demonstration of a novel orbital Feshbach resonance in 173Yb atoms and observation of strongly interacting two-electron fermion gases with anisotropic hydrodynamics.

Findings

Observation of anisotropic hydrodynamic expansion

Realization of a strongly interacting regime at resonance

Potential for new quantum states of matter

Abstract

We report on the experimental observation of a strongly interacting gas of ultracold two-electron fermions with orbital degree of freedom and magnetically tunable interactions. This realization has been enabled by the demonstration of a novel kind of Feshbach resonance occurring in the scattering of two 173Yb atoms in different nuclear and electronic states. The strongly interacting regime at resonance is evidenced by the observation of anisotropic hydrodynamic expansion of the two-orbital Fermi gas. These results pave the way towards the realization of new quantum states of matter with strongly correlated fermions with orbital degree of freedom.