Efimov three-body states on top of a Fermi sea

TL;DR

This paper investigates how the Efimov three-body states are affected when one particle is immersed in a Fermi sea, revealing that Efimov scaling persists and relates to the background fermion density.

Contribution

It demonstrates that Efimov states remain stable in a Fermi sea, establishing a connection between three-body physics and fermionic background density.

Findings

Efimov scaling persists in a Fermi sea environment.

The three-body physics is related to the background fermion density.

The study bridges few-body physics with many-body background effects.

Abstract

The stabilization of Cooper pairs of bound electrons in the background of a Fermi sea is the origin of superconductivity and the paradigmatic example of the striking influence of many-body physics on few-body properties. In the quantum-mechanical three-body problem the famous Efimov effect yields unexpected scaling relations among a tower of universal states. These seemingly unrelated problems can now be studied in the same setup thanks to the success of ultracold atomic gas experiments. In light of the tremendous effect of a background Fermi sea on two-body properties, a natural question is whether a background can modify or even destroy the Efimov effect. Here we demonstrate how the generic problem of three interacting particles changes when one particle is embedded in a background Fermi sea, and show that Efimov scaling persists. It is found in a scaling that relates the three-body physics to the background density of fermionic particles.