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arXiv · 1509.07399

Self-Organized Topological Superconductivity in a Yu-Shiba-Rusinov Chain

M. Schecter·K. Flensberg·M. H. Christensen·B. M. Andersen·J. Paaske
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Abstract

We study a chain of magnetic moments exchange coupled to a conventional three dimensional superconductor. In the normal state the chain orders into a collinear configuration, while in the superconducting phase we find that ferromagnetism is unstable to the formation of a magnetic spiral state. Beyond weak exchange coupling the spiral wavevector greatly exceeds the inverse superconducting coherence length as a result of the strong spin-spin interaction mediated through the subgap band of Yu-Shiba-Rusinov states. Moreover, the simple spin-spin exchange description breaks down as the subgap band crosses the Fermi energy, wherein the spiral phase becomes stabilized by the spontaneous opening of a $p-$wave superconducting gap within the band. This leads to the possibility of electron-driven topological superconductivity with Majorana boundary modes using magnetic atoms on superconducting surfaces.

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M. Schecter, K. Flensberg, M. H. Christensen, B. M. Andersen, J. Paaske. 2015-09-24. Self-Organized Topological Superconductivity in a Yu-Shiba-Rusinov Chain. https://doi.org/10.1103/physrevb.93.140503

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