高温超导体MgB_2的电子结构研究

用第一性原理能带理论计算了高温超导体MgB-2的电子结构.计算得出的电子能带说明MgB-2是一种宽能带化合物，价带主要由Mg和B原子s和p的杂化形成.费米能级处的态密度N(EF)是0.72(states/eV).根据这些结果，初步推断出MgB-2的超导电性的微观机制不可能是电子-声子耦合的BCS模型，而是有待于探索的新机制.

STUDY ON THE ELECTRONIC STRUCTURE OF HIGH-T_C SUPERCONDUCTOR MgB_2

We report a first-principles local density approximation band structure calculation on the electronic structure of high-TC superconductor MgB-2.It is revealed that the band structure of magnesium diboride is of metallic type with a wide valence band.The density of states of electrons at Fermi energy is only about 0.72 (states/eV).We conclude that the present calculation excludes the possibility of BCS mechanism in MgB-2.