Superfluid-insulator transition in Fermi-Bose mixtures and the orthogonality catastrophe

TL;DR

This paper investigates how fermionic screening effects, including an orthogonality catastrophe, alter the superfluid-insulator transition in Fermi-Bose mixtures, providing a mean-field theoretical framework and analyzing observable signatures.

Contribution

It introduces a mean-field approach to incorporate fermionic screening and orthogonality catastrophe effects into the superfluid-insulator transition in Fermi-Bose mixtures.

Findings

Fermionic effects suppress superfluidity in the mixture.

The orthogonality catastrophe influences measurable properties.

Theoretical predictions depend on mixture parameters and temperature.

Abstract

The superfluid-insulator transition of bosons is strongly modified by the presence of Fermions. Through an imaginary-time path integral approach, we derive the self-consistent mean-field transition line, and account for both the static and the dynamic screening effects of the fermions. We find that an effect akin to the fermionic orthogonality catastrophe, arising from the fermionic screening fluctuations, suppresses superfluidity. We analyze this effect for various mixture parameters and temperatures, and consider possible signatures of the orthogonality catastrophe effect in other measurables of the mixture.