Real-space numerical renormalization group computation of transport properties in side-coupled geometry

Article

关键词: DILUTE MAGNETIC-ALLOYS;    ANDERSON MODEL;    STATIC PROPERTIES;    KONDO;    IMPURITIES;    ZERO;   

DOI  :  10.1103/PhysRevB.106.075129

来源: SCIE

【 摘 要 】

A real-space formulation of the numerical renormalization group (NRG) procedure is introduced. The real -space construction, dubbed eNRG, is more straightforward than the NRG discretization, and allows a faithful description of the coupling between quantum dots and conduction states even if the design of the couplings is intricate. General features of the two procedures are discussed comparatively. A more specific comparison is then developed, based on computations of the zero-bias transport properties for an Anderson-model description of a quantum wire side-coupled to a single quantum dot. An eNRG computation is shown to reproduce accurately the temperature-dependent electrical conductance for the uncorrelated model in the continuum limit, while signif-icant deviations mark the corresponding NRG computation for thermal energies comparable to the conduction bandwidth. A combination of analytical and numerical results for the transport properties of the correlated model then provides a more exacting check on the accuracy of the eNRG procedure. A recent NRG analysis mapping the transport properties of a single-electron transistor onto universal functions of the temperature scaled by the Kondo temperature is extended to the side-coupled device, on the basis of eNRG reasoning. Numerical results for the electrical conductance, thermopower, and thermal conductance in side-coupled geometry are then shown to agree very well with the mappings. The numerical results are also checked against the thermal dependence of the thermopower measured by Kohler et al. [Phys. Rev. B 77, 104412 (2008)] in Lu0.9Yb0.1Rh2Si2, and the remarkably accurate, recent conductance measurements by Xu et al. [Chin. Phys. Lett. 38, 087101 (2021)].

【 授权许可】

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