Efficient algorithm for dispersion of YuShibaRusinov chains on a superconducting surface
DIPC Seminars
 Speaker

Rik Broekhoven
Delft University of Technology  When

2024/10/15
12:00  Place
 DIPC Seminar Room
 Host
 Nicolás Lorente Palacios
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Magnetic atoms on swave superconductors locally suppress superconducting pairing, resulting in YuShibaRusinov (YSR) bound states. Chains of YSR states have been proposed to become topological superconductors, when the individual YSR states hybridize and the resulting band is pwave gapped by spinorbit coupling. As recently shown through scanning tunneling microscopy experiments, however, realistic systems have many YSR bands and relatively small spinorbit coupling causing many systems to be topologically trivial. Ab initio models capture the complexity of the realistic system and allow to find the combination of materials and regions of parameter space where the system is topological. The computational costs of these models, however, limit simulations to a finite size of a few nanometers. Thus, simulations must overestimate the superconducting gap to ensure the system is smaller than the superconductor coherence length. We use multidimensional Green’s function formalism as an extension to ab initio calculations to go beyond this limit. We reduce the computational cost of our calculations using shortjunction approximation. This allows us to do calculations with realistic gap size as we verify by testing on few orbital YSR models. We apply our tested algorithm to a Mn chain on Nb (110) as in the 2021 experiment of Schneider et al.