arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1008.0159cond-mat.str-el
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重电子系统中无序对费米面的影响

Effect of Disorder on Fermi surface in Heavy Electron Systems

J. Otsuki, H. Kusunose, Y. Kuramoto

摘要:

本文研究了具有替代无序的近藤晶格模型的费米面尺寸和相应的丁格尔温度。该模型可用于理解重费米子Ce化合物与La按置换Ce{x}La{1-x}合金化。费米面由传导电子动量分布的最陡变化确定,并在足够低的温度下由动力学平均场论(DMFT)结合相干势近似(CPA)导出。没有磁场的费米面的大小随着x从x=1(Ce端)减小而增加,并且在给出与传导电子相同的定域自旋数的x处消失。从x=0(La端)的相反极限开始,费米面随着x的增加而迅速加宽,但保持在与La端相同的位置。随着磁场的增加,发生变磁转变,临界场以上的费米面在整个x范围内连续变化。丁格尔温度在x=0.5附近取最大值。讨论了这些结果对实验观测的意义。

英文摘要:

The Kondo lattice model with substitutional disorder is studied with attention to the size of the Fermi surface and the associated Dingle temperature. The model serves for understanding heavy-fermion Ce compounds alloyed with La according to substitution Ce{x}La{1-x}. The Fermi surface is identified from the steepest change of the momentum distribution of conduction electrons, and is derived at low enough temperature by the dynamical mean-field theory (DMFT) combined with the coherent potential approximation (CPA). The Fermi surface without magnetic field increases in size with decreasing x from x=1 (Ce end), and disappears at such x that gives the same number of localized spins as that of conduction electrons. From the opposite limit of x=0 (La end), the Fermi surface broadens quickly as x increases, but stays at the same position as that of the La end. With increasing magnetic field, a metamagnetic transition occurs, and the Fermi surface above the critical field changes continuously across the whole range of x. The Dingle temperature takes a maximum around x=0.5. Implication of the results to experimental observation is discussed.

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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