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arXiv · 2205.10062

Effect of substrate spin-orbit coupling on the topological gap size of Shiba chains

Philip Beck·Lucas Schneider·Roland Wiesendanger·Jens Wiebe
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Abstract

Realizing Majorana bound states in chains of magnetic impurities on $s$-wave superconducting substrates relies on a fine tuning of the energy and hybridization of the single magnetic impurity bound states and of the spin-orbit coupling (SOC). While recent experiments investigate the influence of the former two parameters, the effect of SOC remained experimentally largely unexplored. Here, we present a scanning tunneling spectroscopy study of close-packed Mn chains along the [001]-direction on Ta(110) which has almost identical atomic and surface electronic structure compared to the previously studied Nb(110) system, but a three times larger SOC. The dominant Shiba band has a very similar dispersion, but its minigap, taken relative to $\varDelta$, is increased by a factor of 1.9 with respect to the Nb case, which can be ascribed to the stronger SOC.

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Philip Beck, Lucas Schneider, Roland Wiesendanger, Jens Wiebe. 2025-04-11. Effect of substrate spin-orbit coupling on the topological gap size of Shiba chains. https://arxiv.org/abs/2205.10062

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