Equilibrium and real-time properties of the spin correlation function in the two-impurity Kondo model
Equilibrium and real-time properties of the spin correlation function in the two-impurity Kondo model
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二杂质Kondo模型中自旋相关函数的平衡性和实时性
DOI：
10.1103/physrevb.98.035109
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
B. Lechtenberg and F. B. Anders
中科院分区：
文献类型：
--
作者：
Ebiloma Godwin U.;Ayuga Teresa Diaz;Balogun Emmanuel O.;Gil Lucia Abad;Donachie Anne;Kaiser Marcel;Herraiz Tomas;Inaoka Daniel K.;Shiba Tomoo;Harada Shigeharu;Kita Kiyoshi;de Koning Harry P.;Dardonville Christophe;Christian Ganser and Takayuki Uchihashi;徳永紘平・高橋嘉夫・香西直文;北村雅人;B. Lechtenberg and F. B. Anders
我们研究了双杂质Kondo模型中不同自旋间距的自旋关联函数的平衡性和实时性质。结果表明，Ruderman-Kittel-Kasuya-Yosida(RKKY)相互作用和近藤效应之间的竞争控制了的幅度。对于超过近藤长度尺度的距离，近藤效应对相关函数的符号也有很大的影响。对于杂质和导带之间的铁磁海森堡耦合，没有近藤效应，关联函数只在有限温度引入的一定长度范围内衰减。系统突然失超后的实时动力学表明，关联随着费米速度在导带中传播。对于长时间行为，我们发现了两个不同的时间尺度，这反映了对于小的系统，系统是由RKKY相互作用驱动的，而对于大的系统，系统是由近藤效应主导的。有趣的是，我们发现，在一定的距离上，一维色散可能导致杂质的局域宇称守恒，从而成为一个长期守恒量，而不会衰变到它的平衡值。
We investigate the equilibrium and real-time properties of the spin-correlation functionin the two-impurity Kondo model for different distancesbetween the two-impurity spins. It is shown that the competition between the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction and the Kondo effect governs the amplitude of. For distancesexceeding the Kondo length scale, the Kondo effect also has a profound effect on the sign of the correlation function. For ferromagnetic Heisenberg couplingsbetween the impurities and the conduction band, the Kondo effect is absent and the correlation function only decays for distances beyond a certain length scale introduced by finite temperature. The real-time dynamics after a sudden quench of the system reveals that correlations propagate through the conduction band with Fermi velocity. We identify two distinct timescales for the long-time behavior, which reflects that for smallthe system is driven by the RKKY interaction while for largethe Kondo effect dominates. Interestingly, we find that at certain distances a one-dimensional dispersion obeyingmay lead to a local parity conservation of the impurities such thatbecomes a conserved quantity for long times and does not decay to its equilibrium value.