Polarons in Alkaline-earth-like Atoms with Multi Background Fermi Surfaces

TL;DR

This paper investigates impurity behavior in a multi-background Fermi sea of $^{173}$Yb atoms near an orbital Feshbach resonance, revealing how multiple Fermi seas influence polaron and molecule properties.

Contribution

It introduces a theoretical framework for studying impurities in a two-channel Fermi system with multiple backgrounds, highlighting the effects of additional Fermi seas on polaron states.

Findings

Additional Fermi sea causes energy shifts between resonance channels.

Fermi level fluctuations significantly affect polaron states.

Presence of multiple Fermi seas alters impurity energy landscape.

Abstract

We study the impurity problem in a Fermi gas of $^{173}$Yb atoms near an orbital Feshbach resonance, where a single moving particle in the $^3P_0$ state interacting with two background Fermi seas of particles in different nuclear states of the ground $^1S_0$ manifold. By employing wave function ansatzs for molecule and polaron states, we investigate various properties of the molecule, the attractive polaron, and the repulsive polaron states. We find that in comparison to the case of only one Fermi sea is populated, the presence of an additional Fermi sea acts as an energy shift between the two channels of the orbital Feshbach resonance. Besides, the fluctuation around the Fermi level would also bring sizable effects to the attractive and repulsive polaron states.