Magnetic field effects in few-level quantum dots: Theory and application to experiment

Article

关键词: NUMERICAL RENORMALIZATION-GROUP;    ELECTRON-TRANSPORT;    KONDO;    ANDERSON;    DYNAMICS;    STATES;    MODEL;    REAL;   

DOI  :  10.1103/PhysRevB.84.115308

来源: SCIE

【 摘 要 】

We examine several effects of an applied magnetic field on Anderson-type models for both single-and two-level quantum dots, and we make direct comparison between numerical renormalization group (NRG) calculations and recent conductance measurements. On the theoretical side, the focus is on magnetization, single-particle dynamics, and zero-bias conductance, with emphasis on the universality arising in strongly correlated regimes, including a method to obtain the scaling behavior of field-induced Kondo resonance shifts over a very wide field range. NRG is also used to interpret recent experiments on spin-1/2 and spin-1 quantum dots in a magnetic field, which we argue do not wholly probe universal regimes of behavior, and the calculations are shown to yield good qualitative agreement with essentially all features seen in experiment. The results capture in particular the observed field dependence of the Kondo conductance peak in a spin-1/2 dot, with quantitative deviations from experiment occurring at fields in excess of similar to 5 T, indicating the eventual inadequacy of using the equilibrium single-particle spectrum to calculate the conductance at finite bias.

【 授权许可】

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