Orbital-selective superconductivity in the nematic phase of FeSe

TL;DR

This paper investigates how nematic order influences orbital-selective superconductivity in FeSe, revealing enhanced orbital selectivity and gap anisotropy that align with experimental observations, advancing understanding of unconventional superconductivity.

Contribution

It introduces a multiorbital model with frustrated spin interactions to explain orbital-selective pairing and gap anisotropy in FeSe's nematic phase, providing new insights into superconductivity mechanisms.

Findings

Orbital-selective pairing enhances gap anisotropy.

Nematic order increases orbital selectivity in pairing.

Results align with recent experimental data.

Abstract

The interplay between electronic orders and superconductivity is central to the physics of unconventional superconductors, and is particularly pronounced in the iron-based superconductors. Motivated by recent experiments on FeSe, we study the superconducting pairing in its nematic phase in a multiorbital model with frustrated spin-exchange interactions. The electron correlations in the presence of the nematic order give rise to an enhanced orbital selectivity in the superconducting pairing amplitudes. This orbital-selective pairing produces a large gap anisotropy on the Fermi surface. Our results naturally explain the striking experimental observations, and shed new light on the unconventional superconductivity of correlated electron systems in general.