# Odd-frequency superconductivity in Sr$_2$RuO$_4$ measured by Kerr rotation

## TL;DR

This paper provides evidence for bulk odd-frequency superconductivity in Sr$_2$RuO$_4$ by linking it to an intrinsic Kerr effect, supported by theoretical models including realistic tight-binding descriptions.

## Contribution

It demonstrates that odd-frequency pairing in Sr$_2$RuO$_4$ arises from orbital hybridization and inter-orbital pairing, establishing a direct link to Kerr effect measurements.

## Key findings

- Bulk odd-frequency superconductivity exists in Sr$_2$RuO$_4$
- Intrinsic Kerr effect is evidence of odd-frequency pairing
- Odd-frequency pairing is enhanced by orbital hybridization and inter-orbital pairing

## Abstract

We establish the existence of bulk odd-frequency superconductivity in Sr$_2$RuO$_4$ and show that an intrinsic Kerr effect is a direct evidence of this state. We use both general two- and three-orbital models, as well as a realistic tight-binding description of Sr$_2$RuO$_4$ to demonstrate that odd-frequency pairing arises due to finite hybridization between different orbitals in the normal state, and is further enhanced by finite inter-orbital pairing.