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Modified Perturbation Theory Applied to Kondo-Type Transport through a Quantum Dot under a Magnetic Field

Osamu Takagi·Tetsuro Saso
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Abstract

Linear conductance through a quantum dot is calculated under a finite magnetic field using the modified perturbation theory. The method is based on the second-order perturbation theory with respect to the Coulomb repulsion, but the self-energy is modified to reproduce the correct atomic limit and to fulfill the Friedel sum rule exactly. Although this method is applicable only to zero temperature in a strict sense, it is approximately extended to finite temperatures. It is found that the conductance near electron-hole symmetry is suppressed by the application of the magnetic field at low temperatures. Positive magnetoconductance is observed in the case of large electron-hole asymmetry.

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Osamu Takagi, Tetsuro Saso. 1999-07-29. Modified Perturbation Theory Applied to Kondo-Type Transport through a Quantum Dot under a Magnetic Field. https://doi.org/10.1143/jpsj.68.2894

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