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arXiv 2201.01860cond-mat.supr-con
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超导 $I$$\overline{4}$3$m$ CSH$_7$ 模型应用于高压压缩 C-S-H 的电阻转变温度数据

Superconducting $I$$\overline{4}$3$m$ CSH$_7$ model applied to resistive transition temperature data for compressed C-S-H at high pressure

Dale R. Harshman, Anthony T. Fiory

AI总结:

本文用理论预测的 $I$$\overline{4}$3$m$ CSH$_7$ 结构和纯电子库仑配对模型解释高压 C-S-H 电阻转变,排除287.7 K数据,并在258、271 GPa下以±3.5 K误差匹配实验。

摘要:

本文更新了第1版,将考虑范围限定为仅电阻数据,并排除了 Snider 等人在 Nature 585, 373 (2020) 中报道的、受到质疑的碳质硫氢化物 287.7 K 数据。超导转变依据 Sun 等人在 Phys. Rev. B 101, 174102 (2020) 中理论发现的压缩 $I$$\overline{4}$3$m$ CSH$_7$ 结构加以考察,该结构包含一个类似于 $Im$$\overline{3}$$m$ H$_3$S 的亚晶格,并嵌有 CH$_4$。在假定超导性具有电子起源的前提下,本文类比早先关于 $Im$$\overline{3}$$m$ H$_3$S 超导性的工作提出一个模型:配对由跨越 S 与包围 C 的 H$_4$ 四面体之间平均距离 ζ 的纯电子库仑相互作用诱导。$I$$\overline{4}$3$m$ CSH$_7$ 的理论超导转变温度推导为 $T$$_{C0}$ = (2/3)$^{1/2}$ $σ^{1/2}$ $β$/$aζ$,其中 $β$ = 1247.4 Å$^2$K 是普适常数,$σ$ 是参与电荷分数,$a$ 是晶格参数。分析表明存在持续的体相超导性,且 $σ$ 依赖于压力:由于额外参与的 C-H 键电子,其从先前为 $Im$$\overline{3}$$m$ H$_3$S 确定的 $σ$ = 3.5 增加到高压下的 $σ$ = 7.5。在由理论结构确定 $a$ 和 ζ 后,对最高压力 258 和 271 GPa 下 $T$$_{C0}$ 的计算与电阻转变相符,总体不确定度在 ±3.5 K 以内。

英文摘要:

This article updates version 1 by restricting consideration to only the resistive data and excluding the questioned 287.7-K datum reported for carbonaceous sulfur hydride in Snider et al., Nature $\textbf{585}$, 373 (2020). The superconducting transitions are considered in terms of the theoretically-discovered compressed $I$$\overline{\textrm{4}}$3$m$ CSH$_7$ structure of Sun et al., Phys. Rev. B $\textbf{101}$, 174102 (2020), which comprises a sublattice similar to $Im$$\overline{\textrm{3}}$$m$ H$_3$S with CH$_4$ intercalates. Positing an electronic genesis of the superconductivity, a model is presented in analogy with earlier work on superconductivity in $Im$$\overline{\textrm{3}}$$m$ H$_3$S, in which pairing is induced via purely electronic Coulomb interactions across the mean distance $ζ$ between the S and H$_4$ tetrahedra enclosing C. Theoretical superconducting transition temperatures for $I$$\overline{\textrm{4}}$3$m$ CSH$_7$ are derived as $T$$_{\textrm{C0}}$ = (2/3)$^{1/2}$ $σ^{1/2}$ $β$/$a$$ζ$, where $β$ = 1247.4 $\mathring{\mathrm{A}}$$^2$K is a universal constant, $σ$ is the participating charge fraction, and $a$ is the lattice parameter. Analysis suggests persistent bulk superconductivity with a pressure-dependent $σ$, increasing from $σ$ = 3.5, determined previously for $Im$$\overline{3}$$m$ H$_3$S, to $σ$ = 7.5 at high pressure owing to additionally participating C-H bond electrons. With $a$ and $ζ$ determined by theoretical structure, calculations of $T$$_{\textrm{C0}}$ at the highest pressures, 258 and 271 GPa, are in agreement with resistive transitions to within an overall uncertainty of $\pm$ 3.5 K.

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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