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arXiv 2106.09265cond-mat.supr-concond-mat.mtrl-scicond-mat.str-el
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量子自旋液体中出现的特殊$π$ -电子超导电性

Extraordinary $π$-Electron Superconductivity Emerging from a Quantum Spin Liquid

Shusaku Imajo, Shiori Sugiura, Hiroki Akutsu, Yoshimitsu Kohama, Takayuki Isono, Taichi Terashima, Koichi Kindo, Shinya Uji, Yasuhiro Nakazawa

摘要:

量子自旋液体(QSL)是一种自旋高度纠缠的液体,被认为是产生奇异超导性的基础。尽管人们做了大量的努力,但由于难以用金属导电性来稳定QSL态,QSL产生的超导性在实际材料中还没有实现。最近,一种有机化合物$κ$ -(BEDT-TTF)$_4$ Hg $_{2.89}$ Br $_8$,具有分子二聚体的几乎规则的三角形晶格,被认为是掺杂QSL的候选物。在这项研究中,我们报告了一个不寻常的超导相的$κ$ -(BEDT-TTF)$_4$ Hg $_{2.89}$ Br $_8$:上临界场与临界温度的比值出乎意料地大$H_{\rm c2}$ / $T_{\rm c}$,不仅在平行于而且垂直于两个-三维导电层和$T_{\rm c}$上方非常宽的波动超导性区域。我们的结果表明,这些特性源于强超导性电子相关性和可能的量子临界性独特的掺杂QSL状态,导致大量的巡回载体和大的超导能隙。

英文摘要:

Quantum spin liquids (QSLs), in which spins are highly entangled, have been considered a groundwork for generating exotic superconductivity.Despite numerous efforts, superconductivity emerging from QSLs has been unrealized in actual materials due to the difficulties in stabilizing QSL states with metallic conductivity.Recently, an organic compound, $κ$-(BEDT-TTF)$_4$Hg$_{2.89}$Br$_8$, with a nearly regular triangular lattice of molecular dimers was recognized as a candidate for doped QSLs. In this study, we report an unusual superconducting phase of $κ$-(BEDT-TTF)$_4$Hg$_{2.89}$Br$_8$: unexpectedly large ratios of the upper critical field to the critical temperature $H_{\rm c2}$/$T_{\rm c}$ in fields not only parallel but also perpendicular to the two-dimensional conducting layers and a very wide region of fluctuating superconductivity above $T_{\rm c}$.Our results reveal that these peculiarities arise from strong electron correlations and possible quantum criticality unique to the doped QSL state, leading to a heavy mass of itinerant carriers and a large superconducting energy gap.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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