Bound states of a ferromagnetic wire in a superconductor

Abstract

We consider the problem of bound states in strongly anisotropic ferromagnetic impurities in a superconductor, motivated by recent experiments that claim to observe Majorana modes at the ends of ferromagnetic wires on a superconducting substrate [S. Nadj-Perge et al., Science 346, 602 (2014)]. Generalizing the successful theory of bound states of spherically symmetric impurities, we consider a wire-like potential using both analytical and numerical approaches. We find that away from the ends of the wire the bound states form bands with pronounced van Hove singularities, giving rise to subgap peaks in the local density of states. For sufficiently strong magnetization of the wire, we show that this process generically produces a sharp peak at zero energy in the local density of states near the ends of the wire. This zero-energy peak has qualitative similarities to the claimed signature of a Majorana mode observed in the aforementioned experiment.

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• Majorana fermions in ferromagnetic chains on the surface of bulk spin-orbit coupled $s$-wave superconductors
• Impurity-induced bound states in superconductors with spin-orbit coupling
• Substrate-induced Majorana renormalization in topological nanowires

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• High-resolution studies of the Majorana atomic chain platform
• Disorder-induced zero-bias peaks in Majorana nanowires
• Experimental Observation of Topological Superconductivity and Majorana Zero Modes on beta-Bi2Pd Thin Films
• Hunting for Majoranas
• Currents induced by magnetic impurities in superconductors with spin-orbit coupling
• Majorana Edge States in Superconductor/Noncollinear Magnet Interfaces
• Bulk disorder in the superconductor affects proximity-induced topological superconductivity
• Detecting topological superconductivity using low-frequency doubled Shapiro steps
• Topological Superconductivity in an s-wave Superconductor and Its Implication to Iron-based Superconductors
• Topological superconductivity in a multichannel Yu-Shiba-Rusinov chain
• Prevalence of trivial zero-energy sub-gap states in non-uniform helical spin chains on the surface of superconductors
• Majorana fermions at odd junctions in a wire network of ferromagnetic impurities
• Topological Superconductivity from Unconventional Band Degeneracy with Conventional Pairing
• Rise and fall of Yu-Shiba-Rusinov bound-states in charge conserving $s$-wave one-dimensional superconductors
• Fate of topological states and mobility edges in one-dimensional slowly varying incommensurate potentials
• Volkov-Pankratov states in topological superconductors
• Majorana quasiparticles in atomic spin chains on superconductors
• Chiral symmetries and Majorana fermions in coupled magnetic atomic chains on a superconductor
• Substrate-induced Majorana renormalization in topological nanowires
• Exactly solving the Kitaev chain and generating Majorana-zero-modes out of noisy qubits
• Topological classification of intrinsic 3D superconductors using anomalous surface construction
• Rashba induced Kondo screening of a magnetic impurity in two-dimensional superconductor
• Fano resonances can provide two criteria to distinguish Majorana bound states from other candidates in experiments
• Majorana-magnon interactions in topological Shiba chains
• Majorana Zero Modes in Ferromagnetic Wires without Spin-Orbit Coupling
• Subgap states and quantum phase transitions in one-dimensional superconductor-ferromagnetic insulator heterostructures
• Inversion-symmetric Electron Gases as New Platforms for Topological Planar Josephson Junctions