Cargando…

Exploring a Proximity-Coupled Co Chain on Pb(110) as a Possible Majorana Platform

[Image: see text] Linear chains of magnetic atoms proximity coupled to an s-wave superconductor are predicted to host Majorana zero modes at the chain ends in the presence of strong spin–orbit coupling. Specifically, iron (Fe) chains on Pb(110) have been explored as a possible system to exhibit topo...

Descripción completa

Detalles Bibliográficos
Autores principales: Ruby, Michael, Heinrich, Benjamin W., Peng, Yang, von Oppen, Felix, Franke, Katharina J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2017
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5515507/
https://www.ncbi.nlm.nih.gov/pubmed/28640633
http://dx.doi.org/10.1021/acs.nanolett.7b01728
_version_ 1783251002811482112
author Ruby, Michael
Heinrich, Benjamin W.
Peng, Yang
von Oppen, Felix
Franke, Katharina J.
author_facet Ruby, Michael
Heinrich, Benjamin W.
Peng, Yang
von Oppen, Felix
Franke, Katharina J.
author_sort Ruby, Michael
collection PubMed
description [Image: see text] Linear chains of magnetic atoms proximity coupled to an s-wave superconductor are predicted to host Majorana zero modes at the chain ends in the presence of strong spin–orbit coupling. Specifically, iron (Fe) chains on Pb(110) have been explored as a possible system to exhibit topological superconductivity and host Majorana zero modes [ S. Nadj-Perge et al., Science2014, 346, 602−60725278507]. Here, we study chains of the transition metal cobalt (Co) on Pb(110) and check for topological signatures. Using spin-polarized scanning tunneling spectroscopy, we resolve ferromagnetic order in the d bands of the chains. Interestingly, also the subgap Yu–Shiba–Rusinov (YSR) bands carry a spin polarization as was predicted decades ago. Superconducting tips allow us to resolve further details of the YSR bands and in particular resonances at zero energy. We map the spatial distribution of the zero-energy signal and find it delocalized along the chain. Hence, despite the ferromagnetic coupling within the chains and the strong spin-orbit coupling in the superconductor, we do not find clear evidence of Majorana modes. Simple tight-binding calculations suggest that the spin–orbit–split bands may cross the Fermi level four times which suppresses the zero-energy modes.
format Online
Article
Text
id pubmed-5515507
institution National Center for Biotechnology Information
language English
publishDate 2017
publisher American Chemical Society
record_format MEDLINE/PubMed
spelling pubmed-55155072017-07-24 Exploring a Proximity-Coupled Co Chain on Pb(110) as a Possible Majorana Platform Ruby, Michael Heinrich, Benjamin W. Peng, Yang von Oppen, Felix Franke, Katharina J. Nano Lett [Image: see text] Linear chains of magnetic atoms proximity coupled to an s-wave superconductor are predicted to host Majorana zero modes at the chain ends in the presence of strong spin–orbit coupling. Specifically, iron (Fe) chains on Pb(110) have been explored as a possible system to exhibit topological superconductivity and host Majorana zero modes [ S. Nadj-Perge et al., Science2014, 346, 602−60725278507]. Here, we study chains of the transition metal cobalt (Co) on Pb(110) and check for topological signatures. Using spin-polarized scanning tunneling spectroscopy, we resolve ferromagnetic order in the d bands of the chains. Interestingly, also the subgap Yu–Shiba–Rusinov (YSR) bands carry a spin polarization as was predicted decades ago. Superconducting tips allow us to resolve further details of the YSR bands and in particular resonances at zero energy. We map the spatial distribution of the zero-energy signal and find it delocalized along the chain. Hence, despite the ferromagnetic coupling within the chains and the strong spin-orbit coupling in the superconductor, we do not find clear evidence of Majorana modes. Simple tight-binding calculations suggest that the spin–orbit–split bands may cross the Fermi level four times which suppresses the zero-energy modes. American Chemical Society 2017-06-22 2017-07-12 /pmc/articles/PMC5515507/ /pubmed/28640633 http://dx.doi.org/10.1021/acs.nanolett.7b01728 Text en Copyright © 2017 American Chemical Society This is an open access article published under an ACS AuthorChoice License (http://pubs.acs.org/page/policy/authorchoice_termsofuse.html) , which permits copying and redistribution of the article or any adaptations for non-commercial purposes.
spellingShingle Ruby, Michael
Heinrich, Benjamin W.
Peng, Yang
von Oppen, Felix
Franke, Katharina J.
Exploring a Proximity-Coupled Co Chain on Pb(110) as a Possible Majorana Platform
title Exploring a Proximity-Coupled Co Chain on Pb(110) as a Possible Majorana Platform
title_full Exploring a Proximity-Coupled Co Chain on Pb(110) as a Possible Majorana Platform
title_fullStr Exploring a Proximity-Coupled Co Chain on Pb(110) as a Possible Majorana Platform
title_full_unstemmed Exploring a Proximity-Coupled Co Chain on Pb(110) as a Possible Majorana Platform
title_short Exploring a Proximity-Coupled Co Chain on Pb(110) as a Possible Majorana Platform
title_sort exploring a proximity-coupled co chain on pb(110) as a possible majorana platform
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5515507/
https://www.ncbi.nlm.nih.gov/pubmed/28640633
http://dx.doi.org/10.1021/acs.nanolett.7b01728
work_keys_str_mv AT rubymichael exploringaproximitycoupledcochainonpb110asapossiblemajoranaplatform
AT heinrichbenjaminw exploringaproximitycoupledcochainonpb110asapossiblemajoranaplatform
AT pengyang exploringaproximitycoupledcochainonpb110asapossiblemajoranaplatform
AT vonoppenfelix exploringaproximitycoupledcochainonpb110asapossiblemajoranaplatform
AT frankekatharinaj exploringaproximitycoupledcochainonpb110asapossiblemajoranaplatform