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arXiv · 1209.3908

The Andreev states of a superconducting quantum dot: mean field vs exact numerical results

A. Martín-Rodero·A. Levy Yeyati
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Abstract

We analyze the spectral density of a single level quantum dot coupled to superconducting leads focusing on the Andreev states appearing within the superconducting gap. We use two complementary approaches: the numerical renormalization group and the Hartree-Fock approximation. Our results show the existence of up to four bound states within the gap when the ground state is a spin doublet (π phase). Furthermore the results demonstrate the reliability of the mean field description within this phase. This is understood from a complete correspondence that can be established between the exact and the mean field quasiparticle excitation spectrum

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A. Martín-Rodero, A. Levy Yeyati. 2012-09-18. The Andreev states of a superconducting quantum dot: mean field vs exact numerical results. https://doi.org/10.1088/0953-8984%2F24%2F38%2F385303

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