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Anisotropic Fully-Gapped Superconductivity Possibly Mediated by Charge Fluctuations in a Nondimeric Organic Complex

Authors :
Masashi Tokunaga
Hiroki Akutsu
K. Kindo
Takeshi Yajima
Shusaku Imajo
Yoshimitsu Kohama
Yasuhiro Nakazawa
Ryosuke Kurihara
Source :
Web of Science
Publication Year :
2020
Publisher :
arXiv, 2020.

Abstract

We investigate low-temperature electronic properties of the nondimeric organic superconductor $\beta^{\prime\prime}$-(BEDT-TTF)$_4$[(H$_3$O)Ga(C$_2$O$_4$)$_3$]PhNO$_2$. By examining ultrasonic properties, charge disproportionation (CD) without magnetic field dependence is detected below $T_{\rm CD}$$\sim$8~K just above the superconducting critical temperature $T_{\rm c}$$\sim$6~K. From quantum oscillations in high fields, we find variation in the Fermi surface and mass enhancement induced by the CD. Heat capacity studies elucidate that the superconducting gap function is fully gapped in the Fermi surface, but anisotropic with fourfold symmetry. We point out that the pairing mechanism of the superconductivity is possibly dominated by charge fluctuations.<br />Comment: 6 figures

Details

Database :
OpenAIRE
Journal :
Web of Science
Accession number :
edsair.doi.dedup.....2e836f9ddd1e32cd1b1395ab8c42fb26
Full Text :
https://doi.org/10.48550/arxiv.2010.03788