Phys. Rev. B 100, 060505(R) (2019) - Microscopic coexistence of superconductivity and charge order in the organic superconductor ${\ensuremath{\beta}}^{\ensuremath{'}\ensuremath{'}}\text{\ensuremath{-}}{(\text{BEDT-TTF})}_{4}[({\mathrm{H}}_{3}\mathrm{O})\mathrm{Ga}{({\mathrm{C}}_{2}{\mathrm{O}}_{4})}_{3}]\phantom{\rule{0.16em}{0ex}}\ifmmode\cdot\else\textperiodcentered\fi{}\phantom{\rule{0.16em}{0ex}}{\mathrm{C}}_{6}{\mathrm{H}}_{5}{\mathrm{NO}}

Rapid Communication

Microscopic coexistence of superconductivity and charge order in the organic superconductor $β^{''} − {(BEDT-TTF)}_{4} [(H_{3} O) Ga {(C_{2} O_{4})}_{3}] \cdot C_{6} H_{5} {NO}_{2}$

Y. Ihara, K. Moribe, S. Fukuoka, and A. Kawamoto

Phys. Rev. B 100, 060505(R) – Published 20 August 2019

Abstract

An electron paramagnetic resonance study for an organic superconductor $β^{''} − {(BEDT-TTF)}_{4} [(H_{3} O) Ga {(C_{2} O_{4})}_{3}] \cdot C_{6} H_{5} {NO}_{2}$ 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 an exotic charge ordered state, in which molecular-site-selective carrier localization coexists with conducting carriers on other molecules. The relationship between superconductivity and this conductive charge ordered state is investigated.