New mechanism and exact theory of superconductivity from strong repulsive interaction

TL;DR

This paper proposes a new mechanism for superconductivity driven by strong repulsive interactions, using an analytical approach that relates critical temperature to microscopic parameters, and suggests new routes for unconventional pairing and superfluidity.

Contribution

It introduces a novel, analytically-controlled theory of superconductivity based on correlated multi-particle tunneling in strongly repulsive Fermi systems, with quantitative predictions for $T_c$.

Findings

Maximum $T_c$ reaches about 10% of Fermi temperature.

Provides a formula relating $T_c$ to microscopic parameters.

Demonstrates a new method for studying unconventional superconductivity.

Abstract

We introduce a new and general mechanism for superconductivity in Fermi systems with strong repulsive interaction. Because kinetic terms are small compared to the bare repulsion, the dynamic of charge carriers is constrained by the the presence of other nearby carriers. By treating kinetic terms as a perturbation around the atomic limit, we show that pairing can be induced by correlated multi-particle tunneling processes that favor two itinerant carriers to be close together. Our analytically-controlled theory provides a quantitative formula relating $T_c$ to microscopic parameters, with maximum $T_c$ reaching about 10% of the Fermi temperature. Our work demonstrates a powerful method for studying strong coupling superconductivity with unconventional pairing symmetry. It also offers a realistic new route to realizing finite angular momentum superfluidity of spin-polarized fermions in optical lattice.