Hidden non-Fermi-liquid behavior due to a crystal-field quartet
Hidden non-Fermi-liquid behavior due to a crystal-field quartet
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由于晶体场四重奏而隐藏的非费米液体行为
DOI：
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发表时间：
1999
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通讯作者：
M. Koga
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作者：
M. Koga
本文采用数值重整化群方法，研究了具有磁性和非磁性（四极）交换耦合与传导电子的晶体场四重奏基态的现实Kondo模型。我们重点研究了依赖于单线态激发态与四重奏耦合的局部效应，该效应显著降低了非磁耦合，并驱动了计算的四极磁化率中观察到的非费米-液体行为。从非费米-液体状态到费米-液体状态的交叉具有小的能量尺度，对非磁耦合非常敏感。另一方面，近藤温度对观察到的磁化率不太敏感。这两种交换偶联的不同晶体场依赖性可能与Ce{sub x}La{sub 1-x}B{sub 6}中四极和磁序温度的不同x依赖性有关。(c) 2000年美国物理学会。
We study a realistic Kondo model for crystal field quartet ground states having magnetic and nonmagnetic (quadrupolar) exchange couplings with conduction electrons, using the numerical renormalization group method. We focus on a local effect dependent on singlet excited states coupled to the quartet, which reduces the nonmagnetic coupling significantly and drives non-Fermi-liquid behavior observed in the calculated quadrupolar susceptibility. A crossover from the non-Fermi-liquid state to the Fermi-liquid state is characterized by a small energy scale very sensitive to the nonmagnetic coupling. On the other hand, the Kondo temperature observed in the magnetic susceptibility is less sensitive. The different crystal-field dependence of the two exchange couplings may be related to the different x dependence of quadrupolar and magnetic ordering temperatures in Ce{sub x}La{sub 1-x}B{sub 6}. (c) 2000 The American Physical Society.