Semimetallic SDW State in Quasi One-Dimensional Conductors
Semimetallic SDW State in Quasi One-Dimensional Conductors
复制标题
准一维导体中的半金属 SDW 态
DOI：
10.1143/jpsj.51.2787
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发表时间：
1982
影响因子：
1.7
通讯作者：
K. Yamaji
中科院分区：
文献类型：
--
作者：
K. Yamaji
研究了体现(TMTSF) 2 PF 6 等特征的准一维Hubbard模型。求解了由变分法导出的SDW间隙方程。间隙参数是在 OK 和有限温度下作为横向电子转移能量 t ' 的函数导出的。 SDW 转变被证明是第二阶的。当间隙变得小于带极值的调制幅度时，由于t'的有限值，由SDW间隙分开的上带和下带开始重叠。还获得了将 SDW 相分为半导体相和半金属相的温度。简要描述了态密度、磁阻、电导率、磁化率等物理性质。如果我们取 t'∼300 k B 并假设 t' 具有适当的压力依赖性，则实验观察结果与上述结果定性地一致。
A quasi one-dimensional Hubbard model embodying features of (TMTSF) 2 PF 6 etc. was studied. The SDW gap equation derived by a variational method is solved. The gap parameter is derived at OK and at finite temperatures as a function of the transverse electron transfer energy t '. The SDW transition proves to be of the second order. The upper and lower bands separated by the SDW gap start to overlap due to finite value of t ' when the gap becomes smaller than the magnitude of modulation of band extrema. The temperature dividing the SDW phase into semiconducting and semimetallic phases is also obtained. Physical properties such as state density, magnetoresistivity, conductivity, susceptibility etc. are briefly described. Experimental observations agree qualitatively well with the above results, if we take t '∼300 k B and assume appropriate pressure dependence of t '.