Topological superconductivity in carbon nanotubes with a small magnetic flux

We show that a one-dimensional topological superconductor can be realized in carbon nanotubes, using a relatively small magnetic field. Our analysis relies on the intrinsic curvature-enhanced spin-orbit coupling of the nanotubes, as well as on the orbital effect of a magnetic flux threaded through t...

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Main Authors: Omri Lesser, Gal Shavit, Yuval Oreg
Format: Article
Language:English
Published: American Physical Society 2020-06-01
Series:Physical Review Research
Online Access:http://doi.org/10.1103/PhysRevResearch.2.023254
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author Omri Lesser
Gal Shavit
Yuval Oreg
author_facet Omri Lesser
Gal Shavit
Yuval Oreg
author_sort Omri Lesser
collection DOAJ
description We show that a one-dimensional topological superconductor can be realized in carbon nanotubes, using a relatively small magnetic field. Our analysis relies on the intrinsic curvature-enhanced spin-orbit coupling of the nanotubes, as well as on the orbital effect of a magnetic flux threaded through the nanotube. Tuning experimental parameters, we show that a half-metallic state may be induced in the nanotube. Coupling the system to an Ising superconductor, with an appreciable spin-triplet component, can then drive the nanotube into a topological superconducting phase. The proposed scheme is investigated by means of real-space tight-binding simulations, accompanied by an effective continuum low-energy theory, which allows us to gain some insight on the roles of different terms in the Hamiltonian. We calculate the topological phase diagram and ascertain the existence of localized Majorana zero modes near the edges. Moreover, we find that in the absence of a magnetic field, a regime exists where sufficiently strong interactions drive the system into a time-reversal-invariant topological superconducting phase.
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spelling doaj.art-0f5adcfba02b47e3856c4cbbcd85dac32024-04-12T16:54:47ZengAmerican Physical SocietyPhysical Review Research2643-15642020-06-012202325410.1103/PhysRevResearch.2.023254Topological superconductivity in carbon nanotubes with a small magnetic fluxOmri LesserGal ShavitYuval OregWe show that a one-dimensional topological superconductor can be realized in carbon nanotubes, using a relatively small magnetic field. Our analysis relies on the intrinsic curvature-enhanced spin-orbit coupling of the nanotubes, as well as on the orbital effect of a magnetic flux threaded through the nanotube. Tuning experimental parameters, we show that a half-metallic state may be induced in the nanotube. Coupling the system to an Ising superconductor, with an appreciable spin-triplet component, can then drive the nanotube into a topological superconducting phase. The proposed scheme is investigated by means of real-space tight-binding simulations, accompanied by an effective continuum low-energy theory, which allows us to gain some insight on the roles of different terms in the Hamiltonian. We calculate the topological phase diagram and ascertain the existence of localized Majorana zero modes near the edges. Moreover, we find that in the absence of a magnetic field, a regime exists where sufficiently strong interactions drive the system into a time-reversal-invariant topological superconducting phase.http://doi.org/10.1103/PhysRevResearch.2.023254
spellingShingle Omri Lesser
Gal Shavit
Yuval Oreg
Topological superconductivity in carbon nanotubes with a small magnetic flux
Physical Review Research
title Topological superconductivity in carbon nanotubes with a small magnetic flux
title_full Topological superconductivity in carbon nanotubes with a small magnetic flux
title_fullStr Topological superconductivity in carbon nanotubes with a small magnetic flux
title_full_unstemmed Topological superconductivity in carbon nanotubes with a small magnetic flux
title_short Topological superconductivity in carbon nanotubes with a small magnetic flux
title_sort topological superconductivity in carbon nanotubes with a small magnetic flux
url http://doi.org/10.1103/PhysRevResearch.2.023254
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AT galshavit topologicalsuperconductivityincarbonnanotubeswithasmallmagneticflux
AT yuvaloreg topologicalsuperconductivityincarbonnanotubeswithasmallmagneticflux