Materials design and fabrication of new superconductors based on choice of elements and band structure control

我们首先从理论上解决了一个长期存在的难题，即即使在高Tc铜酸盐的单层家族中，也存在很强的材料依赖性，这超出了传统的观点，即铜酸盐是单带系统。Cu d轨道之间的能量差已被证明是一个关键的量支配Tc。在此基础上，解释了压力对Tc的影响。这些被概括为“轨道蒸馏效应”，也可以应用于化学压力，从而为材料设计提供指导原则。对于多层铜氧化物，层间对隧道被揭示，以提高Tc。在实验上，制备了新的Mott绝缘体Ba_2IrO_4，测量了FeSe的压力效应，发现了具有赝AlB_2结构的Ba（TM，Si）_2的超导电性，发现了具有Sb四面体结构的新的超导体SrPt_2Sb_2。在这些材料中，理论结构优化和电子结构计算相结合，以获得更高的Tc和新材料的制造指南。

We first theoretically resolved a long-standing puzzle that there is a strong material-dependence even within the single-layer family of high-Tc cuprates by going beyond the conventional belief that the cuprates are single-band systems. The energy difference between Cu d orbitals has turned out to be a key quantity governing Tc. Based on this, the pressure effect on Tc has also been explained. These are summarised into an "orbital distillation effect", which can also be applied to chemical pressure, thereby providing a guiding principle for materials design. For multi-layer cuprates, the inter-layer pair tunnelling is revealed to enhance Tc. Experimentally, a new Mott insulator Ba2IrO4 is fabricated, a pressure effect on FeSe is measured, superconductiviti is discovered for Ba(TM,Si)2 with a pseudo AlB2 structure, and a new superconductor SrPt2Sb2 having Sb tetrahedra is discovered. In these materials, theoretical structure optimisation and electronic structure calculation are combined to obtain guides for higher Tc and fabrication of new materials.