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arXiv 1102.1154cond-mat.mes-hallcond-mat.str-el
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单Mn离子量子点的近藤屏蔽机制

Kondo screening regimes of a quantum dot with a single Mn ion

E. vernek, Fanyao Qu, F. M. Souza, J. C. Egues, E. V. Anda

摘要:

研究了磁性Mn离子与金属引线连接的量子点的近藤和输运性质。通过采用数值重整化群技术,我们表明,依赖于本地电子自旋和磁矩的Mn之间的铁磁耦合强度的值,存在两个不同的近藤制度。在弱耦合极限下,系统处于完全屏蔽的近藤态,描述了与系统其余部分解耦的局部磁矩。相比之下,在强耦合区域中,量子点的自旋和局域磁矩形成了一个大自旋的实体,部分被近藤屏蔽。通过改变量子点电子和引线之间的隧道耦合,可以适当地调节这两种状态之间的交叉。该模型也适用于研究磁性分子在金属表面的吸附。这些系统的丰富现象学反映在系统的电导中。

英文摘要:

We study the Kondo and transport properties of a quantum dot with a single magnetic Mn ion connected to metallic leads. By employing a numerical renormalization group technique we show that depending on the value of ferromagnetic coupling strength between the local electronic spin and the magnetic moment of the Mn, two distinct Kondo regimes exist. In the weak coupling limit, the system can be found in a completely screened Kondo state describing a local magnetic moment decoupled from the rest of the system. In contrast, in the strong coupling regime the quantum dot spin and the local magnetic moment form a single large-spin entity partially Kondo screened. A crossover between these two regimes can be suitably tuned by varying the tunnel coupling between the quantum dot electron and the leads. The model investigated here is also suitable to study magnetic molecules adsorbed on a metallic surface. The rich phenomenology of these systems is reflected in the conductance across the system.

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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