高压下高温超导材料YBa_2Cu_3O_7的电子结构

THE ELECTRONIC STRUCTURE OF HIGH TEMPERATURE SUPERCONDUCTING MATERIAL YBa_2Cu_3O_7 UNDER HIGH PRESSURE

本文选用拟合能带的 Harrison参数构造紧束缚哈密顿矩阵,采取Recursion 方法计算了 YBa_2Cu_3O_7晶体在常压下与9 GPa高压下(此时晶格常数压缩 3％)的电子结构。讨论了高压对于电子结构的影响。给出了高压下费米面移动、能带展宽和各晶位原子价变化的定量结果。

The electronic structure of YBa2Cu3O7 under atmosphere and 9GPa high pressure (under which the crystal constants are contracted by 3%) are calculated, respectively. In calculation, recursion method is used and the tight binding Hamiltonian is constructed by Harrison parameters fitted to energy band. The influence of high pressure on electronic structure is discussed. The quantitative results about shift of Fermi surface, widening of energy band width and varying of atomic valence of each crystal site are given.