Two-fermion bound state in a Bose-Einstein condensate

TL;DR

This paper predicts a novel two-fermion bound state within a Bose-Einstein condensate, derived from a nonlinear Schrödinger equation describing ultracold fermionic atoms interacting with condensate phonons, suggesting new experimental signatures.

Contribution

It introduces a new theoretical framework for fermion-condensate interactions and predicts a two-fermion bound state arising from phonon-mediated nonlinear effects.

Findings

Prediction of a two-fermion bound state

Derivation of a nonlinear Schrödinger equation for fermion-condensate dynamics

Discussion of experimental signatures in atom optics

Abstract

A nonlinear Schr\"odinger equation is derived for the dynamics of a beam of ultracold fermionic atoms traversing a Bose-Einstein condensate. The condensate phonon modes are shown to provide a nonlinear medium for the fermionic atoms. A two-fermion bound state is predicted to arise, and the signature of the bound state in a nonlinear atom optics experiment is discussed.