Kondo effect in single-molecule magnet transistors
Kondo effect in single-molecule magnet transistors
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DOI：
10.1103/physrevb.78.054445
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发表时间：
2008-08-01
影响因子：
3.7
通讯作者：
Mucciolo, Eduardo R.
中科院分区：
文献类型：
--
作者：
Gonzalez, Gabriel;Leuenberger, Michael N.;Mucciolo, Eduardo R.
我们提出了一个仔细和彻底的微观推导的各向异性近藤哈密顿单分子磁铁（SMM）晶体管。当分子与金属导线强耦合时，我们证明了在自旋S > 1/2的整数或半整数SMM电导中，通过施加横向磁场，可以拓扑诱导或猝灭近藤效应.这种拓扑近藤效应是由于自旋的多个量子隧穿路径之间的贝里相位干涉。利用Poor man标度法计算了近藤两个峰的重整化Berry相振荡随横向磁场的变化。特别是，我们表明，近藤交换之间的相互作用的巡游电子的铅和SMM赝自旋1/2取决于至关重要的SMM自旋选择规则的添加和减去的电子，可以从反铁磁到铁磁。我们说明我们的研究结果与SMM Ni-4，我们建议作为一个可能的候选人的电导振荡的实验观察。
We present a careful and thorough microscopic derivation of the anisotropic Kondo Hamiltonian for single-molecule magnet (SMM) transistors. When the molecule is strongly coupled to metallic leads, we show that by applying a transverse magnetic field it is possible to topologically induce or quench the Kondo effect in the conductance of a SMM with either an integer or a half-integer spin S > 1/2. This topological Kondo effect is due to the Berry-phase interference between multiple quantum tunneling paths of the spin. We calculate the renormalized Berry-phase oscillations of the two Kondo peaks as a function of the transverse magnetic field by means of the poor man's scaling. In particular, we show that the Kondo exchange interaction between itinerant electrons in the leads and the SMM pseudospin 1/2 depends crucially on the SMM spin selection rules for the addition and subtraction of an electron and can range from antiferromagnetic to ferromagnefic. We illustrate our findings with the SMM Ni-4, which we propose as a possible candidate for the experimental observation of the conductance oscillations.