arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1004.0670cond-mat.mes-hall
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自旋轨道介观干涉仪中的近藤效应

Kondo effect in spin-orbit mesoscopic interferometers

Jong Soo Lim, Mircea Crisan, David Sanchez, Rosa Lopez, Ioan Grosu

摘要:

我们考虑一个内嵌量子点的磁通螺纹Aharonov-Bohm环与两个正常引线耦合。作用于量子点电子的局域Rashba自旋轨道相互作用导致除了由外磁通引起的Aharonov-Bohm相位之外的自旋相关相位因子。利用数值重整化群方法,我们发现了近藤共振在费米能级处的分裂,这种分裂可以被外加磁场补偿。为了充分理解这种补偿效应的性质,我们进行了缩放分析,并推导出有效磁场的表达式。分析是基于紧束缚模型,导致一个有效的安德森模型与自旋相关的态密度的转换铅态。我们发现,有效场起源于Rashba相互作用和磁通量的联合作用,它包含了重要的修正,由于电子-电子相互作用。我们表明,补偿场是一个振荡函数的自旋轨道和Aharonov-Bohm相位。此外,有效场永远不会消失,由于粒子-空穴对称性破缺独立的栅极电压。

英文摘要:

We consider a flux-threaded Aharonov-Bohm ring with an embedded quantum dot coupled to two normal leads. The local Rashba spin-orbit interaction acting on the dot electrons leads to a spin-dependent phase factor in addition to the Aharonov-Bohm phase caused by the external flux. Using the numerical renormalization group method, we find a splitting of the Kondo resonance at the Fermi level which can be compensated by an external magnetic field. To fully understand the nature of this compensation effect, we perform a scaling analysis and derive an expression for the effective magnetic field. The analysis is based on a tight-binding model which leads to an effective Anderson model with a spin-dependent density of states for the transformed lead states. We find that the effective field originates from the combined effect of Rashba interaction and magnetic flux and that it contains important corrections due to electron-electron interactions. We show that the compensating field is an oscillatory function of both the spin-orbit and the Aharonov-Bohm phases. Moreover, the effective field never vanishes due to the particle-hole symmetry breaking independently of the gate voltage.

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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