# Microscopic coexistence of superconductivity and charge order in organic superconductor $\beta''$-(BEDT-TTF)$_{4}$[(H$_3$O)Ga(C$_2$O$_4$)$_3$]$\cdot$C$_6$H$_5$NO$_2$

## TL;DR

This study demonstrates the microscopic coexistence of superconductivity and charge order in an organic superconductor, revealing anisotropic electronic behavior and a unique charge ordered state with selective carrier localization.

## Contribution

It provides new insights into the coexistence of superconductivity and charge order in organic materials, highlighting the anisotropic nature of the charge ordered state.

## Key findings

- Superconductivity coexists with charge order in the material.
- Interplane spin exchange is gapped in the charge ordered state.
- In-plane conductivity remains largely unaffected.

## Abstract

The electron paramagnetic resonance study for an organic superconductor $\beta''$-(BEDT-TTF)$_{4}$[(H$_3$O)Ga(C$_2$O$_4$)$_3$]$\cdot$C$_6$H$_5$NO$_2$ reveals that superconductivity coexists uniformly with the charge ordered state in one material. In the charge ordered state, the interplane spin exchange is gapped, while the in-plane conductivity is not significantly modified. This anisotropic behavior is explained by the exotic charge ordered state, in which molecular-site selective carrier localization coexists with conducting carriers on other molecules. Relationship between superconductivity and this conductive charge ordered state is investigated.