Coulomb blockade and Kondo effect in the electronic structure of Hubbard molecules connected to metallic leads: A finite-temperature exact-diagonalization study
Coulomb blockade and Kondo effect in the electronic structure of Hubbard molecules connected to metallic leads: A finite-temperature exact-diagonalization study
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连接到金属引线的哈伯德分子电子结构中的库仑封锁和近藤效应：有限温度精确对角化研究
DOI：
10.1103/physrevb.86.205115
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发表时间：
2012
影响因子：
3.7
通讯作者：
H. Ishida and A.Liebsch
中科院分区：
文献类型：
--
作者：
H. Ishida;A. Liebsch;H. Ishida and A.Liebsch
在低偏压极限下，研究了耦合在两个半无限长导线之间的Hubbard小分子的电子结构。为了计算系统的有限温度绿色函数，每个铅被模拟成一个小的集群，使问题减少到一个有限大小的系统，包括分子和两侧的集群。铅簇的哈密顿参数的选择，使其嵌入电位与那些半无限的铅松原频率。精确对角化用于评估库仑相关性对有限温度下分子电子性质的影响。根据关键的哈密顿参数，如库仑排斥，单电子跳跃的分子，分子和铅之间的杂交，分子的自能表现出费米液体行为或偏差与有限的低能量散射率。该方法被证明是足够准确地描述形成的近藤共振内的相关引起的赝隙，除了在极低的温度的限制。这些结果表明，该系统如何可以调整之间的库仑阻塞和近藤制度。
The electronic structure of small Hubbard molecules coupled between two noninteracting semi-infinite leads is studied in the low bias-voltage limit. To calculate the finite-temperature Green's function of the system, each lead is simulated by a small cluster, so that the problem is reduced to that of a finite-size system comprising the molecule and clusters on both sides. The Hamiltonian parameters of the lead clusters are chosen such that their embedding potentials coincide with those of the semi-infinite leads on Matsubara frequencies. Exact diagonalization is used to evaluate the effect of Coulomb correlations on the electronic properties of the molecule at finite temperature. Depending on key Hamiltonian parameters, such as Coulomb repulsion, one-electron hopping within the molecule, and hybridization between molecule and leads, the molecular self-energy is shown to exhibit Fermi-liquid behavior or deviations associated with finite low-energy scattering rates. The method is shown to be sufficiently accurate to describe the formation of Kondo resonances inside the correlation-induced pseudogaps, except in the limit of extremely low temperatures. These results demonstrate how the system can be tuned between the Coulomb blockade and Kondo regimes.