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arXiv 2007.06640cond-mat.supr-con
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超导加压LaH $_{10}$的光学性质

Optical properties of superconducting pressurized LaH$_{10}$

Sabri Elatresh, T. Timusk, E. J. Nicol

摘要:

最近在硫化氢体系和氢化镧体系中分别在200~K和260~K附近发现了超导电性,这两个体系的压力都在200 GPa左右。这些破纪录的转变温度使获得室温超导性的长期目标触手可及。我们使用基于密度泛函理论(DFT)的第一性原理计算以及Migdal-Eliashberg理论来研究LaH $_{10}$超导体中$Fm\bar{3}m$相的超导电性的电子-声子机制。我们发现,非常高的转变温度$T_c$的结果从一个高度优化的电子-声子相互作用,有利于耦合到高频氢声子。计算了各种超导性质,如能隙、同位素效应、$T_c$处的比热跃变、热力学临界场和随温度变化的穿透深度。然而,我们的主要重点是有限频率的光学性质,测量可以允许一个独立的确定$T_c$,也确认超导机制。

英文摘要:

Recently superconductivity has been discovered at around 200~K in a hydrogen sulfide system and around 260~K in a lanthanum hydride system, both under pressures of about 200 GPa. These record-breaking transition temperatures bring within reach the long-term goal of obtaining room temperature superconductivity. We have used first-principle calculations based on density functional theory (DFT) along with Migdal-Eliashberg theory to investigate the electron-phonon mechanism for superconductivity in the $Fm\bar{3}m$ phase proposed for the LaH$_{10}$ superconductor. We show that the very high transition temperature $T_c$ results from a highly optimized electron-phonon interaction that favors coupling to high frequency hydrogen phonons. Various superconducting properties are calculated, such as the energy gap, the isotope effect, the specific heat jump at $T_c$, the thermodynamic critical field and the temperature-dependent penetration depth. However, our main emphasis is on the finite frequency optical properties, measurement of which may allow for an independent determination of $T_c$ and also a confirmation of the mechanism for superconductivity.

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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