ANDERSON MODEL OUT OF EQUILIBRIUM - NONCROSSING-APPROXIMATION APPROACH TO TRANSPORT THROUGH A QUANTUM-DOT

Article

关键词: CONSISTENT PERTURBATION-THEORY;    CONDUCTANCE OSCILLATIONS;    MIXED-VALENCE;    ELECTRON;    IMPURITY;    SYSTEMS;    STATES;    SPECTROSCOPY;    LIMIT;   

DOI  :  10.1103/PhysRevB.49.11040

来源: SCIE

【 摘 要 】

The infinite-U Anderson model is applied to transport through a quantum dot. The current and density of states are obtained via the noncrossing approximation for two spin-degenerate levels weakly coupled to two leads. At low temperatures, the Kondo peak in the equilibrium density of states strongly enhances the linear-response conductance. Application of a finite voltage bias reduces the conductance and splits the peak in the density of states. The split peaks, one at each chemical potential, are suppressed in amplitude by a finite dissipative lifetime. We estimate this lifetime perturbatively as the time to transfer an electron from the higher-chemical-potential lead to the lower-chemical-potential one. At zero magnetic field, the clearest signatures of the Kondo effect in transport through a quantum dot are the broadening, shift, and enhancement of the linear-response conductance peaks at low temperatures, and a peak in the nonlinear differential conductance around zero bias.

【 授权许可】

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