2021/02/23 by Shusaku Imajo, Koichi Kindo, Yasuhiro Nakazawa · 13 citations
Materials Science · Mathematics · Physics and Astronomy · #Magnetism in coordination complexes #Mathematics #Organic and Molecular Conductors Research #Physics #Solid-state spectroscopy and crystallography #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.103.l060508
published in Physical review. B./Physical review. B 103(6) (American Physical Society) · 5 figures
arxiv created 2021/02/23 · openalex publication_date 2021/02/25 · openalex created_date 2021/03/01 · arxiv updated 2021/03/17 · openalex updated_date 2026/08/05
Magnetic-field-angle-resolved heat capacity of dimer-Mott organic superconductors \ensuremathκ\text\ensuremath-(BEDT\text\ensuremath-TTF)2X is reported (BEDT-TTF and X represent bis(ethylenedithio)tetrathiafulvalene and a monovalent anion, respectively). Temperature and field dependence of heat capacity indicates that the superconductivity has line nodes on the Fermi surface, which is a typical feature of d-wave superconductivity. In-plane field-angle dependence exhibits fourfold oscillations as well as twofold oscillations due to anisotropy of superconducting gap functions. From analyses of the fourfold term, the gap symmetry is determined as d_x2\ensuremath-y2+s_\ifmmode±\else\textpm\fi for X=Cu[N(CN)2]Br and dxy for X=Ag(CN)2H2O. We suggest that the symmetry difference comes from the competition of dxy and d_x2\ensuremath-y2 antiferromagnetic fluctuations depending on lattice geometry.