Fermi-surface evolution across the magnetic phase transition in the Kondo lattice model
Fermi-surface evolution across the magnetic phase transition in the Kondo lattice model
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DOI：
10.1103/physrevb.78.155127
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发表时间：
2008-07
影响因子：
3.7
通讯作者：
N. Lanatà;P. Barone;M. Fabrizio
中科院分区：
文献类型：
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作者：
N. Lanatà;P. Barone;M. Fabrizio
我们利用扩展的Gutzveler波函数，在Gutzveler近似下，导出了Kondo晶格模型的相图。我们发现，一般情况下，即在没有嵌套的情况下，模型表现出$f电子的Mott局域化，伴随着传导电子费米面的不连续变化以及磁性的变化。当非相互作用费米面接近嵌套时，Mott局域化从磁性开始就解开了。首先，顺磁重费米子金属连续地转变为巡回磁体，费米面在转变过程中平稳演化，随后费米面的不连续重排干扰了Mott局域化。我们发现，即使磁化被阻止，电子的局域化仍然存在，并且仍然伴随着布里渊区内费米能级的谱重急剧转移。我们进一步证明，外加磁场也可以诱导Mott局域化，在这种情况下，Mott局域化伴随着变磁相变而发生。
We derive, by means of an extended Gutzwiller wave function and within the Gutzwiller approximation, the phase diagram of the Kondo lattice model. We find that generically, namely, in the absence of nesting, the model displays an $f$-electron Mott localization accompanied by a discontinuous change of the conduction-electron Fermi surface as well as by magnetism. When the noninteracting Fermi surface is close to nesting, the Mott localization disentangles from the onset of magnetism. First the paramagnetic heavy-fermion metal turns continuously into an itinerant magnet\char22{}the Fermi surface evolves smoothly across the transition\char22{}and afterward Mott localization intervenes with a discontinuous rearrangement of the Fermi surface. We find that the $f$-electron localization remains even if magnetism is prevented and is still accompanied by a sharp transfer of spectral weight at the Fermi energy within the Brillouin zone. We further show that the Mott localization can be also induced by an external magnetic field, in which case it occurs concomitantly with a metamagnetic transition.