Magnetic Field Effects on Transport Properties of a Quantum Dot Studied by Modified Perturbation Theory
Magnetic Field Effects on Transport Properties of a Quantum Dot Studied by Modified Perturbation Theory
复制标题
修正微扰理论研究磁场对量子点输运性质的影响
DOI：
10.1143/jpsj.68.1997
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发表时间：
1999
影响因子：
1.7
通讯作者：
T. Saso
中科院分区：
文献类型：
--
作者：
O. Takagi;T. Saso
提出了一种计算用杂质安德森模型表示的量子点激发谱的新方案。它是基于二阶微扰理论与库仑排斥，但修改，以重现正确的原子限制，并履行弗里德尔总和规则。研究了磁场对量子点的激发光谱和输运性质的影响。研究发现，在外加磁场作用下，微分电导的零偏压峰发生分裂，当电子-空穴不对称时，在零偏压下出现负磁阻效应。
A new scheme is proposed for calculating excitation spectrum of a quantum dot expressed by the impurity Anderson model. It is based on the second order perturbation theory with respect to the Coulomb repulsion, but is modified so as to reproduce the correct atomic limit and to fulfil the Friedel sum rule. The magnetic field dependence of both the excitation spectra and the transport properties of a quantum dot is investigated. It is found that the zero bias peak in differential conductance splits under external magnetic field and that negative magnetoresistance will be observed at zero bias voltage in case of electron-hole asymmetry.