A Theory of Anisotropic Semiconductor of Heavy Fermions
A Theory of Anisotropic Semiconductor of Heavy Fermions
复制标题
重费米子各向异性半导体理论
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
K. Miyake
中科院分区：
文献类型：
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作者：
H. Ikeda;K. Miyake
它表明，一个k -依赖的f -和传导电子之间的杂交矩阵元可以引起各向异性的杂交间隙的重费米子，如果电子的填充对应于带绝缘体。当杂化沿着反映晶体场特殊对称性的晶体对称轴消失时，发生最有趣的情况。模型计算的结果与在CeNiSn及其同构化合物（重费米子的各向异性半导体）中观察到的广泛的反常性质是一致的。特别是，杂质散射对零能激发剩余态密度的高灵敏度效应和电阻率的各向异性温度依赖性得到了很好的解释。还讨论了由于f电子自能Δ f（k，0）的弱k依赖性而产生的弱半金属行为.
It is demonstrated that a k -dependence of the hybridization matrix element between f - and conduction electrons can give rise to an anisotropic hybridization gap of heavy fermions if the filling of electrons corresponds to that of the band insulator. The most interesting case occurs when the hybridization vanishes along some symmetry axis of the crystal reflecting a particular symmetry of the crystal field. The results of a model calculation are consistent with wide range of anomalous properties observed in CeNiSn and its isostructural compounds, the anisotropic semiconductor of heavy fermions. In particular, highly sensitive effect of impurity scattering on the residual density of states for zero energy excitation and the anisotropic temperature dependence of the resistivity are well explained. It is also discussed that a weak semimetallic behavior arises through the weak k -dependence of the f -electron self-energy Σ f ( k ,0).