arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1903.03255cond-mat.supr-con
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H3X(X=As,Se,Br,Sb,Te和I)的压力诱导高温超导性

Pressure-induced high temperature superconductivity in H3X (X=As, Se, Br, Sb, Te and I)

P. -H. Chang, S. Silayi, D. A. Papaconstantopoulos, M. J. Mehl

摘要:

在高度压缩的H_{3} S中发现的高临界温度T_{c}超导性,开启了在过渡金属系列之外的超导体中寻找强电子-声子耦合的问题。这项工作的具体目标是探索发现超过H_{3} S超导转变温度的材料的可能性。我们的研究包括材料H_{3} X(X=As、Se、Br、Sb、Te和I),仅限于Im \overline{3} m晶体结构。我们采用的程序包括进行线性化增广平面波计算许多不同的体积计算电子态密度和它们的压力变化。这是结合量子ESTERO计算,我们得到的声子频率和电子-声子耦合常数λ,然后应用多次散射为基础的理论Gaspari和Gyorffy,以获得Hopfield参数和McMillan-Allen-Dynes理论。应该强调的是,GG方法将电子对λ的贡献从相应的声子贡献中分离出来,并为理解这些材料中的超导性提供了额外的见解。根据我们的分析,氢是这些材料中T_{c}的主要贡献者,因为它占总λ的75 \sim 80%。我们对H_{3} Se和H_{3} Br的计算给出了T_{c} {}{} \sim 100 K.对于我们研究中的其他材料,我们发现H_{3} As是不稳定的,H_{3} Sb、H_{3} Te和H_{3} I具有小的McMillan-Hopfield参数值,这使得它不太可能给出高的T_{c}。然而,根据我们的刚性带模型和虚拟晶体计算,我们预测一个T_{c} \sim 150 K的H_{3} Br与少量的氢掺杂。

英文摘要:

The discovery of high critical temperature T_{c} superconductivity in highly compressed H_{3}S has opened up the question of searching for strong electron-phonon coupling in the hydrides outside the transition metal series. The specific objective of this work is to explore the possibility of discovering a material that exceeds the superconducting transition temperature of H_{3}S. Our study includes the materials H_{3}X (X=As, Se, Br, Sb, Te, and I), is limited to the Im\overline{3}m crystal structure. The procedure we adopt involves performing linearized augmented plane wave calculations for many different volumes to compute the electronic densities of states and their pressure variation. This is combined with Quantum-ESPRESSO calculations from which we obtain the phonon frequencies and the electron-phonon coupling constant λ, and followed by applying the multiple scattering-based theory of Gaspari and Gyorffy to obtain the Hopfield parameters and the McMillan-Allen-Dynes theory. It should be stressed that the GG approach decouples the electronic contribution to λfrom the corresponding phonon contribution, and provides additional insights for the understanding of superconductivity in these materials. Based on our analysis, the hydrogen is the main contributor to the T_{c} in these materials as it makes up 75\sim80 % of the total λ. Our calculations for H_{3}Se and H_{3}Br give a T_{c}{}{}\sim100 K. For the other materials in our study we find that H_{3}As is unstable and H_{3}Sb, H_{3}Te and H_{3}I have small values of the McMillan-Hopfield paramters which makes it unlikely to give high T_{c}. However, according to both of our rigid band model and virtual crystal calculations, we predict a T_{c}\sim150 K for H_{3}Br with a small amount of hydrogen doping.

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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