Semiconductor-ferromagnet-superconductor planar heterostructures for 1D topological superconductivity

Hybrid structures of semiconducting (SM) nanowires, epitaxially grown superconductors (SC), and ferromagnetic-insulator (FI) layers have been explored experimentally and theoretically as alternative platforms for topological superconductivity at zero magnetic field. Here, we analyze a tripartite SM/...

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Bibliographic Details
Published innpj quantum materials Vol. 7; no. 1; pp. 1 - 8
Main Authors Escribano, Samuel D., Maiani, Andrea, Leijnse, Martin, Flensberg, Karsten, Oreg, Yuval, Levy Yeyati, Alfredo, Prada, Elsa, Seoane Souto, Rubén
Format Journal Article
LanguageEnglish
Published London Nature Publishing Group UK 18.08.2022
Nature Publishing Group
Nature Portfolio
Subjects
639/301/119/1003
639/301/119/2792
639/925/357/1016
Condensed Matter Physics
Den kondenserade materiens fysik
Epitaxial growth
Ferromagnetism
Fysik
Heterostructures
Hybrid structures
Hybrid systems
Magnetic fields
Magnetic properties
Nanowires
Natural Sciences
Naturvetenskap
Physical Sciences
Physics
Physics and Astronomy
Quantum Physics
Stacking
Structural Materials
Superconductivity
Superconductors
Surfaces and Interfaces
Thin Films
Topology
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Summary:Hybrid structures of semiconducting (SM) nanowires, epitaxially grown superconductors (SC), and ferromagnetic-insulator (FI) layers have been explored experimentally and theoretically as alternative platforms for topological superconductivity at zero magnetic field. Here, we analyze a tripartite SM/FI/SC heterostructure but realized in a planar stacking geometry, where the thin FI layer acts as a spin-polarized barrier between the SM and the SC. We optimize the system’s geometrical parameters using microscopic simulations, finding the range of FI thicknesses for which the hybrid system can be tuned into the topological regime. Within this range, and thanks to the vertical confinement provided by the stacking geometry, trivial and topological phases alternate regularly as the external gate is varied, displaying a hard topological gap that can reach half of the SC one. This is a significant improvement compared to setups using hexagonal nanowires, which show erratic topological regions with typically smaller and softer gaps. Our proposal provides a magnetic field-free planar design for quasi-one-dimensional topological superconductivity with attractive properties for experimental control and scalability.
ISSN:2397-4648
2397-4648
DOI:10.1038/s41535-022-00489-9