Moiré Surface States and Enhanced Superconductivity in Topological Insulators

Recently, moiré superlattices have been found on the surface of topological insulators due to the rotational misalignment of topmost layers. In this work, we study the effects of moiré superlattices on the topological surface states using a continuum model of Dirac electrons moving in a periodic pot...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Taige Wang, Noah F. Q. Yuan, Liang Fu
Formato:	article
Lenguaje:	EN
Publicado:	American Physical Society 2021
Materias:	Physics QC1-999
Acceso en línea:	https://doaj.org/article/4022c7359cf5401e8ce3d81084ca8f13
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:4022c7359cf5401e8ce3d81084ca8f13
record_format	dspace
spelling	oai:doaj.org-article:4022c7359cf5401e8ce3d81084ca8f132021-12-02T17:34:53ZMoiré Surface States and Enhanced Superconductivity in Topological Insulators10.1103/PhysRevX.11.0210242160-3308https://doaj.org/article/4022c7359cf5401e8ce3d81084ca8f132021-04-01T00:00:00Zhttp://doi.org/10.1103/PhysRevX.11.021024http://doi.org/10.1103/PhysRevX.11.021024https://doaj.org/toc/2160-3308Recently, moiré superlattices have been found on the surface of topological insulators due to the rotational misalignment of topmost layers. In this work, we study the effects of moiré superlattices on the topological surface states using a continuum model of Dirac electrons moving in a periodic potential. Unlike twisted bilayer graphene, moiré surface states cannot host isolated bands due to their topological nature. Instead, we find (high-order) van Hove singularities (VHS) in the moiré band structure that give rise to divergent density of states (DOS) and enhance interaction effects. Because of spin-momentum locking in moiré surface states, possible interaction channels are limited. In the presence of phonon mediated attraction, superconductivity is strongly enhanced by the power-law divergent DOS at high-order VHS. The transition temperature T_{c} exhibits a power-law dependence on the retarded electron-phonon interaction strength λ^{*}. This enhancement is found to be robust under various perturbations from the high-order VHS.Taige WangNoah F. Q. YuanLiang FuAmerican Physical SocietyarticlePhysicsQC1-999ENPhysical Review X, Vol 11, Iss 2, p 021024 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	Physics QC1-999
spellingShingle	Physics QC1-999 Taige Wang Noah F. Q. Yuan Liang Fu Moiré Surface States and Enhanced Superconductivity in Topological Insulators
description	Recently, moiré superlattices have been found on the surface of topological insulators due to the rotational misalignment of topmost layers. In this work, we study the effects of moiré superlattices on the topological surface states using a continuum model of Dirac electrons moving in a periodic potential. Unlike twisted bilayer graphene, moiré surface states cannot host isolated bands due to their topological nature. Instead, we find (high-order) van Hove singularities (VHS) in the moiré band structure that give rise to divergent density of states (DOS) and enhance interaction effects. Because of spin-momentum locking in moiré surface states, possible interaction channels are limited. In the presence of phonon mediated attraction, superconductivity is strongly enhanced by the power-law divergent DOS at high-order VHS. The transition temperature T_{c} exhibits a power-law dependence on the retarded electron-phonon interaction strength λ^{*}. This enhancement is found to be robust under various perturbations from the high-order VHS.
format	article
author	Taige Wang Noah F. Q. Yuan Liang Fu
author_facet	Taige Wang Noah F. Q. Yuan Liang Fu
author_sort	Taige Wang
title	Moiré Surface States and Enhanced Superconductivity in Topological Insulators
title_short	Moiré Surface States and Enhanced Superconductivity in Topological Insulators
title_full	Moiré Surface States and Enhanced Superconductivity in Topological Insulators
title_fullStr	Moiré Surface States and Enhanced Superconductivity in Topological Insulators
title_full_unstemmed	Moiré Surface States and Enhanced Superconductivity in Topological Insulators
title_sort	moiré surface states and enhanced superconductivity in topological insulators
publisher	American Physical Society
publishDate	2021
url	https://doaj.org/article/4022c7359cf5401e8ce3d81084ca8f13
work_keys_str_mv	AT taigewang moiresurfacestatesandenhancedsuperconductivityintopologicalinsulators AT noahfqyuan moiresurfacestatesandenhancedsuperconductivityintopologicalinsulators AT liangfu moiresurfacestatesandenhancedsuperconductivityintopologicalinsulators
_version_	1718379935941263360

Moiré Surface States and Enhanced Superconductivity in Topological Insulators

Ejemplares similares