Spiral magnetic order and topological superconductivity in a chain of magnetic adatoms on a two-dimensional superconductor

Abstract

We study the magnetic and electronic phases of a 1D magnetic adatom chain on a 2D superconductor. In particular, we confirm the existence of a `self-organized' 1D topologically non-trivial superconducting phase within the set of subgap Yu-Shiba-Rusinov (YSR) states formed along the magnetic chain. This phase is stabilized by incommensurate spiral correlations within the magnetic chain that arise from the competition between short-range ferromagnetic and long-range antiferromagnetic electron-induced exchange interactions, similar to a recent study for a 3D superconductor [M. Schecter et al. Phys. Rev. B 93, 140503(R) 2016]. The exchange interaction along diagonal directions are also considered and found to display behavior similar to a 1D substrate when close to half filling. We show that the topological phase diagram is robust against local superconducting order parameter suppression and weak substrate spin-orbit coupling. Lastly, we study the effect of a direct ferromagnetic exchange coupling between the adatoms, and find the region of spiral order in the phase diagram to be significantly enlarged in a wide range of the direct exchange coupling.

12 pages, 13 figures, published version

References in corpus (8)

• Majorana Fermions and a Topological Phase Transition in Semiconductor-Superconductor Heterostructures
• Observation of Majorana Fermions in Ferromagnetic Atomic Chains on a Superconductor
• Spin-selective Peierls transition in interacting one-dimensional conductors with spin-orbit interaction
• Topological Superconductivity induced by Ferromagnetic Metal Chains
• Strong localization of Majorana end states in chains of magnetic adatoms
• Topological Yu-Shiba-Rusinov chain from spin-orbit coupling
• Interplay of topological phases in magnetic adatom-chains on top of a Rashba superconducting surface
• Self-organized topological state in the magnetic chain on the surface of a superconductor

Cited by in corpus (6)

• Tuning interactions between spins in a superconductor
• Topological properties of chains of magnetic impurities on a superconducting substrate: Interplay between the Shiba band and ferromagnetic wire limits
• Aspects of topological superconductivity in 2D systems: noncollinear magnetism, skyrmions, and higher-order topology
• Topological superconductivity at finite temperatures in proximitized magnetic nanowires
• Quasiparticle focusing of bound states in two-dimensional $s$-wave superconductors
• Spin-polarized zero-bias peak from a single magnetic impurity at an s-wave superconductor: first-principles study