Impurity-induced pairing in two-dimensional Fermi gases
Abstract
We study induced pairing between two identical fermions mediated by an attractively interacting quantum impurity in two-dimensional systems. Based on a Stochastic Variational Method (SVM), we investigate the influence of confinement and finite interaction range effects on the mass ratio beyond which the ground state of the quantum three-body problem undergoes a transition from a composite bosonic trimer to an unbound dimer-fermion state. We find that confinement as well as a finite interaction range can greatly enhance trimer stability, bringing it within reach of experimental implementations such as found in ultracold atom systems. In the context of solid-state physics, our solution of the confined three-body problem shows that exciton-mediated interactions can become so dominant that they can even overcome detrimental Coulomb repulsion between electrons in atomically-thin semiconductors. Our work thus paves the way towards a universal understanding of boson-induced pairing across various fermionic systems at finite density, and opens perspectives towards realizing novel forms of electron pairing beyond the conventional paradigm of Cooper pair formation.
Cite
@article{arxiv.2211.12495,
title = {Impurity-induced pairing in two-dimensional Fermi gases},
author = {Ruipeng Li and Jonas von Milczewski and Atac Imamoglu and Rafał Ołdziejewski and Richard Schmidt},
journal= {arXiv preprint arXiv:2211.12495},
year = {2023}
}
Comments
21 pages, 15 figures