First-principles band structure and FLEX approach to the pressure effect on Tc of the cuprate superconductors

24th IUPAP Conference on Computational Physics

物理学;计算机科学

Sakakibara, Hirofumi^1 ; Suzuki, Katsuhiro^1 ; Usui, Hidetomo^1 ; Kuroki, Kazuhiko^1 ; Arita, Ryotaro^2,5 ; Scalapino, Douglas J.^3 ; Aoki, Hideo^4

Department of Engineering Science, University of Electro-Communications, Chofu, Tokyo 182-8585, Japan^1

Department of Applied Physics, University of Tokyo, Hongo, Tokyo 113-8656, Japan^2

Physics Department, University of California, Santa Barbara, CA 93106-9530, United States^3

Department of Physics, University of Tokyo, Hongo, Tokyo 113-0033, Japan^4

JST, PRESTO, Kawaguchi, Saitama 332-0012, Japan^5

关键词: Ambient pressures;    Apical oxygen;    Band calculation;    First principles;    High-temperature cuprate superconductors;    Orbital components;    Pyramidal coordination;    Renormalization;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/454/1/012021/pdf
DOI  :  10.1088/1742-6596/454/1/012021

学科分类：计算机科学（综合）

来源: IOP

【 摘 要 】

High-temperature cuprate superconductors have been known to exhibit significant pressure effects. In order to fathom the origin of why and how Tcis affected by pressure, we have recently studied the pressure effects on Tcadopting a model that contains two copper d-orbitals derived from first-principles band calculations, where the dz2orbital is considered on top of the usually considered dx2-y2orbital. In that paper, we have identified two origins for the Tcenhancement under hydrostatic pressure: (i) while at ambient pressure the smaller the hybridization of other orbital components the higher the Tc, an application of pressure acts to reduce the multiorbital mixing on the Fermi surface, which we call the orbital distillation effect, and (ii) the increase of the band width with pressure also contributes to the enhancement. In the present paper, we further elaborate the two points. As for point (i), while the reduction of the apical oxygen height under pressure tends to increase the dz2mixture, hence to lower Tc, here we show that this effect is strongly reduced in bi-layer materials due to the pyramidal coordination of oxygen atoms. As for point (ii), we show that the enhancement of Tcdue to the increase in the band width is caused by the effect that the many-body renormalization arising from the self-energy is reduced.