# Driving force of the orbital-relevant electronic nematicity in Fe-based superconductors

## TL;DR

This paper proposes a strong-coupling mechanism where virtual hopping processes reduce Hubbard energy, driving orbital-relevant nematic charge order, and linking it to spin magnetism and superconductivity in Fe-based superconductors.

## Contribution

It introduces a unified microscopic mechanism explaining electronic nematicity, spin magnetism, and superconductivity through virtual hopping processes reducing Hubbard energy.

## Key findings

- Virtual hopping processes drive orbital-relevant nematic charge order.
- The same processes induce spin magnetic order and pairing interactions.
- Electronic nematicity, magnetism, and superconductivity are interconnected.

## Abstract

The electronic nematic responses in Fe-based superconductors have been observed ubiquitously in various experimental probes. One novel nematic character is the d-wave {\it bond} orbital-relevant nematic charge order which was firstly proposed by symmetry analysis and then conformed by angle-resolved photoemission spectroscopy. In this paper, we present a mechanism that the driving force of the orbital-relevant nematic charge order is the reduction of the large Hubbard energy in the particle-hole charge channel by virtual hopping processes. This is one scenario from strong-coupling consideration. The same virtual hopping processes can lead to a super-exchange interaction for the spin magnetic order in the particle-hole spin channel and a pairing interaction for the superconducting order in the particle-particle channel. Thus the electronic nematic order, the spin magnetic order and the pairing superconducting order are intrinsically entangled and they can all stem from the same microscopic virtual hopping processes in reduction of the Hubbard energy. The electronic nematicity, the spin magnetism and the pairing superconductivity in unconventional superconductors are proposed to be unified within this mechanism.