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arXiv · 2308.14227

Fulde-Ferrell-Larkin-Ovchinnikov state induced by antiferromagnetic order in $\kappa$-type organic conductors

Shuntaro Sumita·Makoto Naka·Hitoshi Seo
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Abstract

We theoretically investigate superconductivity under a spin-split band structure owing to a collinear-type antiferromagnetic order in quasi-two-dimensional organic compounds $\kappa$-(BEDT-TTF)$_2X$. We find that the magnetic order can induce a Fulde--Ferrell--Larkin--Ovchinnikov (FFLO) state, where the Cooper pair possesses a finite center-of-mass momentum. We show this from two types of analyses: (1) an effective model where simple intraband attractive interactions are assumed, and (2) many-body calculations of the repulsive Hubbard model based on the fluctuation-exchange approximation and the linearized Eliashberg equation. Our results show the possibility of realizing the FFLO state without applying an external magnetic field.

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Shuntaro Sumita, Makoto Naka, Hitoshi Seo. 2023-08-27. Fulde-Ferrell-Larkin-Ovchinnikov state induced by antiferromagnetic order in $\kappa$-type organic conductors. https://doi.org/10.1103/physrevresearch.5.043171

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