标题： 局部铜-氧态的自旋交叉对高温超导铜氧化物电子结构的影响 显示英文标题

标题： Effect of the spin crossover of local copper-oxygen states on the electronic structure of HTSC cuprates

摘要： 在本工作中，研究了沿c轴的单轴压力对高温超导铜氧化物La2-xSrxCuO4电子结构的影响，在掺杂水平x = 0.1、0.15、0.25处进行研究。 在五带p-d模型框架内使用GTB方法来描述电子系统。 单轴压缩导致电子结构的显著重构以及低能准粒子激发特性的变化：价带顶部出现了a1g对称轨道的大贡献。 在压力Pc = 15.1 GPa处发现了局部Zhang-Rice三重态与Emery-Reiter三重态之间的转变。 在压力下的电子结构特征变化是由于这种转变而突然发生的。 特别是，价带顶部移动到k点（pi,0）附近的区域，费米面轮廓转变为围绕（0,0）、（2pi,0）、（0,2pi）、（2pi,2pi）的四个袋状结构以及围绕（pi,pi）的一个轮廓。 显示英文摘要

摘要： In this work, the effect of uniaxial pressure along the c axis on the electronic structure of the HTSC cuprate La2-xSrxCuO4 is investigated at the doping levels x = 0.1, 0.15, 0.25. The GTB method within the five-band p-d model framework is used to describe the electron system. The uniaxial compression leads to a significant reconstruction of the electronic structure and a change in the character of low-energy quasiparticle excitations: a large contribution of a1g symmetry orbitals appears at the top of the valence band. The crossover between the local Zhang-Rice singlet and the Emery-Reiter triplet was found at the pressure Pc = 15.1 GPa. The characteristic changes in the electronic structure under pressure occur abruptly as a result of the crossover. In particular, the top of the valence band displaces to the region around the k-point (pi,0), the Fermi contour transforms to the four pockets around (0,0),(2pi,0),(0,2pi),(2pi,2pi) and the one contour around (pi,pi).