Yu-Shiba-Rusinov screening of spins in double quantum dots
| Autor: | Grove-Rasmussen, K., Steffensen, G., Jellinggaard, A., Madsen, M. H., Žitko, R., Paaske, J., Nygård, J. |
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| Rok vydání: | 2017 |
| Předmět: | |
| Zdroj: | Nature Communications 9, 2376 (2018) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1038/s41467-018-04683-x |
| Popis: | A magnetic impurity coupled to a superconductor gives rise to a Yu-Shiba-Rusinov (YSR) state inside the superconducting energy gap. With increasing exchange coupling the excitation energy of this state eventually crosses zero and the system switches to a YSR groundstate with bound quasiparticles screening the impurity spin by $\hbar/2$. Here we explore InAs nanowire double quantum dots tunnel coupled to a superconductor and demonstrate YSR screening of spin-1/2 and spin-1 states. Gating the double dot through 9 different charge states, we show that the honeycomb pattern of zero-bias conductance peaks, archetypal of double dots coupled to normal leads, is replaced by lines of zero-energy YSR states. These enclose regions of YSR-screened dot spins displaying distinctive spectral features, and their characteristic shape and topology change markedly with tunnel coupling strengths. We find excellent agreement with a simple zero-bandwidth approximation, and with numerical renormalization group calculations for the two-orbital Anderson model. Comment: 6 pages, 4 figures. For Supplementary Information, see http://www.kaspergr.dk/YSRDQD/SupplementaryInformation.pdf |
| Databáze: | arXiv |
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