Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

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

Escribano, Samuel D. ; Maiani, Andrea ; Leijnse, Martin LU ; Flensberg, Karsten ; Oreg, Yuval ; Levy Yeyati, Alfredo ; Prada, Elsa and Seoane Souto, Rubén LU orcid (2022) In npj Quantum Materials 7(1).
Abstract

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... (More)

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.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
npj Quantum Materials
volume
7
issue
1
article number
81
publisher
Nature Publishing Group
external identifiers
  • scopus:85136738006
ISSN
2397-4648
DOI
10.1038/s41535-022-00489-9
language
English
LU publication?
yes
id
e0b90e06-dba8-43fb-988c-2a139c7bb344
date added to LUP
2022-10-17 08:31:25
date last changed
2023-11-21 01:58:32
@article{e0b90e06-dba8-43fb-988c-2a139c7bb344,
  abstract     = {{<p>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.</p>}},
  author       = {{Escribano, Samuel D. and Maiani, Andrea and Leijnse, Martin and Flensberg, Karsten and Oreg, Yuval and Levy Yeyati, Alfredo and Prada, Elsa and Seoane Souto, Rubén}},
  issn         = {{2397-4648}},
  language     = {{eng}},
  month        = {{12}},
  number       = {{1}},
  publisher    = {{Nature Publishing Group}},
  series       = {{npj Quantum Materials}},
  title        = {{Semiconductor-ferromagnet-superconductor planar heterostructures for 1D topological superconductivity}},
  url          = {{http://dx.doi.org/10.1038/s41535-022-00489-9}},
  doi          = {{10.1038/s41535-022-00489-9}},
  volume       = {{7}},
  year         = {{2022}},
}