Kondo Resistivity due to a Pair of Interacting Impurities
Kondo Resistivity due to a Pair of Interacting Impurities
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由于一对相互作用的杂质而产生的近藤电阻率
DOI：
10.1103/physrev.178.874
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发表时间：
1969
期刊：
影响因子：
--
通讯作者：
M. Béal
中科院分区：
文献类型：
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作者：
M. Béal
利用近藤哈密顿量，计算了由于导电电子被溶解在非磁性基质中的一对相互作用的磁性杂质散射而产生的近藤型电阻率，它是杂质与它们的耦合W之间距离R的函数，散射幅度的能量可达三阶。对于小的WkBT和大的R，对的电阻率降低到一个孤立杂质的近藤电阻率的两倍；对于大的WkBT和小的R，这对实际上是一个单一的自旋，并给出一个对应于自旋1的近藤电阻率，或者(取决于W的符号)完全不依赖于自旋的电阻率-对应于自旋0。对于中间的W，验证了(取W为Rudermann-Kittel-Yosida间接相互作用)两个相关杂质的反常近藤电阻率(降温时)比两个孤立的非相互作用杂质的电阻率增加得慢，这与实验一致。因此，当浓度不足以忽略杂质之间的相互关系时，这一简单的方法可以用来描述铜-锰型稀合金的电阻率。
The Kondo-type resistivity due to the scattering of conduction electrons by a pair of interacting magnetic impurities of spin ½ dissolved in a nonmagnetic host is calculated as a function of the distance R between the impurities and their coupling W. The Kondo Hamiltonian is used, and the scattering amplitudes are calculated up to third order in energy. For small W k B T and large R, the resistivity of the pair reduces to twice the Kondo resistivity of one isolated impurity; for large W k B T and small R, the pair acts practically as one single spin, and gives a Kondo resistivity—corresponding to spin of 1, or (depending on the sign of W), no spin-dependent resistivity at all—corresponding to a spin of 0. For intermediate W, one verifies (taking for W the Rudermann-Kittel-Yosida indirect interaction) that the anomalous Kondo resistivity of two correlated impurities increases less rapidly (for decreasing temperature) than the resistivity of two isolated noninteracting impurities; this is in agreement with experiments. Therefore, it is suggested that this simple procedure may be useful to describe the resistivity of dilute alloys of Cu Mn type, when the concentration is not sufficiently small to neglect the correlations between the impurities.