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arXiv 1012.2255cond-mat.str-el
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Kondo晶格模型的低能性质

Low-energy properties of the Kondo lattice model

O. Bodensiek, R. Zitko, R. Peters, T. Pruschke

摘要:

在动力学平均场论的框架下研究了近藤晶格模型的零温性质。作为杂质解,我们使用了数值重整化群。我们目前的顺磁性的情况下,显示预期的重费米子物理,包括直接证据的外观反铁磁交换相互作用的大费米表面的结果。允许形成一个尼尔状态,我们观察到在有限掺杂的反铁磁金属低于临界交换相互作用,这表明从局部矩反铁磁体与一个小费米表面弱交换耦合到一个重费米子反铁磁体与一个大费米表面增加交换的交叉。包括晶格自由度通过一个额外的Holstein项,我们观察到一个显着的抑制近藤效应,导致强烈降低低能尺度。对于过大的电子-声子耦合,我们发现重费米液体的完全散射和极化子的形成。

英文摘要:

We study the zero-temperature properties of the Kondo lattice model within the dynamical mean-field theory. As impurity solver we use the numerical renormalization group. We present results for the paramagnetic case showing the anticipated heavy Fermion physics, including direct evidence for the appearance of a large Fermi surface for antiferromagnetic exchange interaction. Allowing for the formation of a Neel state, we observe at finite doping an antiferromagnetic metal below a critical exchange interaction, which shows a crossover from a local-moment antiferromagnet with a small Fermi surface for weak exchange coupling to a heavy-fermion antiferromagnet with a large Fermi surface for increasing exchange. Including lattice degrees of freedom via an additional Holstein term we observe a significant suppression of the Kondo effect, leading to strongly reduced lowenergy scale. For too large electron-phonon coupling we find a complete collaps of the heavy Fermi liquid and the formation of polarons.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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