Majorana Coupling and Kondo Screening of Localized Spins
K.P. Wójcika, b, P. Majekc
aInstitute of Physics, Maria Curie-Skłodowska University, pl. Marii Curie-Skłodowskiej 1, 20-031 Lublin, Poland
bInstitute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, 60-179 Poznań, Poland
cISQI, Faculty of Physics, Adam Mickiewicz University, Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland
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We perform a theoretical analysis of the fate of the local magnetic moment of a quantum dot coupled to a normal metallic lead and a topological superconducting wire hosting Majorana modes at the ends. By means of simple analytical tools and numerical renormalization group calculations, we show that the proximity of the Majorana mode reduces the magnetic moment from 1/4, characteristic of a free spin 1/2, to 1/16. Coupling to the normal lead then causes the Kondo effect, such that the magnetic moment is fully screened below the Kondo temperature. The latter is vastly increased for strong coupling to Majorana mode.

DOI:10.12693/APhysPolA.143.207
topics: Majorana wire, Kondo effect, magnetic moment, numerical renormalization group