Kondo Effect Due to Impurities with (5f)n Configuration: Fermi Liquid Versus Non-Fermi Liquid
Kondo Effect Due to Impurities with (5f)n Configuration: Fermi Liquid Versus Non-Fermi Liquid
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(5f)n 配置杂质引起的近藤效应：费米液体与非费米液体
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
H. Shiba
中科院分区：
文献类型：
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作者：
M. Koga;H. Shiba
结合费米液体和非费米液体的稳定性，研究了U型杂质引起的近藤效应。首先，对于与多个5f电子耦合的传导电子，导出了用不可约张量算符表示的有效交换哈密顿量。它是基于强自旋轨道和Hund耦合的假设。其次，通过将内部结构简化为非Kramers双基态和第一单重态激发态，研究了位于四方晶场或六方晶场中的f2组态模型。数值重整化群分析表明，在非费米液体中，单重态激发态对稳定费米液体起着重要作用。第三，考察了立方晶场作用下f2的非Kramers二重态和f3的Kramers二重态的Kondo效应的差异。结果表明，对于f3，Hund耦合使通道数减少到1个，而对于F3，情况则不同。
The Kondo effect due to U-type impurities is studied in connection with the stability of the Fermi liquid and the non-Fermi liquid. First, an effective exchange Hamiltonian in terms of irreducible tensor operators is derived for conduction electrons, which are coupled with plural 5 f electrons. It is based on the assumption of strong spin-orbit and Hund couplings. Second, a model for f 2 configuration placed in a tetragonal or hexagonal crystal field is studied by simplifying the internal structure as the non-Kramers doublet ground state and the first singlet excited state. The numerical renormalization group analysis shows that the singlet excited state plays an important role to stabilize the Fermi liquid over the non-Fermi liquid. Third, the difference of the Kondo effect is examined between non-Kramers doublet for f 2 and Kramers doublet for f 3 in the presence of the cubic crystal field. It is shown that for f 3 the Hund coupling reduces the channel number to one, while the situation is different for...