双Tl-O层Tl-Ba-Ca-Cu氧化物超导体的能带结构

ENERGY BAND STRUCTURES OF DUBLE Tl-O LAYER Tl-Ba-Ca-Cu OXIDE SUPERCONDUCTORS

利用EHT近似下的紧束缚能带结构计算方法计算了Tl-Ba-Ca-Cu氧化物超导体双Tl-O层体系的能带结构。计算结果表明费米面在a~*b~*面上是封闭的,费米能级上电子态密度的增加和体系转变湿度(T_c)的提高是相一致的。Cu-O面上Cu和O的净电荷有规律的变化说明,Cu-O面上Cu和O的离子价态可影响该体系的超导电性。

We calculated the energy band structures of the double TI-O layer TI-Ba-Ca-CuO oxide superconductors by performing the tight-binding band structure calculation method on the basis of EHT approximation. The results show that the Fermi surfacesare closed on the a~*b~* plane. The increase of electronic state densities on the Fermilevel is consistent with the raise of T_c in this system. The regular changing of thenet charges of Cu and O indicates that the ionic states of Cu and O in Cu-O planemay influence the superconductivity of this system.