2025/05/16 by Yano, Shota, Katsuki Kinjo, Fukushima, Kazumi +15
Materials Science · #FOS: Physical sciences #Magnetism in coordination complexes #Materials Science (cond-mat.mtrl-sci) #Organic and Molecular Conductors Research #Solid-state spectroscopy and crystallography #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con)
paper · pdf · doi:10.48550/arxiv.2505.11333
openalex publication_date 2025/05/16 · openalex created_date 2025/10/05 · openalex updated_date 2026/07/28
In the quasi-one-dimensional organic unconventional superconductor (TMTSF)2ClO4, the randomness of the non-centrosymmetric ClO4 anions can be experimentally controlled by adjusting the cooling rate through the anion-ordering temperature. This feature provides a unique opportunity to study disorder effects on unconventional superconductivity in great detail. We here report on measurements of the electronic specific heat of this system, performed under various cooling rates. The evolution of the residual density of states indicates that the ClO4 randomness works as Born-limit pair breakers, which, to our knowledge, has never been clearly identified in any unconventional superconductors. Furthermore, detailed analyses suggest a peculiar crossover from strong unitarity scattering due to molecular defects toward the Born-limit weak scattering due to borders of ordered regions. This work supports the d-wave nature of pairing in (TMTSF)2ClO4 and intends to provide an experimental basis for further developments of pair-breaking theories of unconventional superconductors where multiple electron scattering mechanisms coexist.