Intrinsic first- and higher-order topological superconductivity in a doped topological insulator

Scammell, HD; Ingham, J; Geier, M; Li, T

Intrinsic first- and higher-order topological superconductivity in a doped topological insulator

Scammell, HD Ingham, J Geier, M Li, T

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Publisher:: American Physical Society (APS)
Publication Type:: Journal Article
Citation:: Physical Review B, 2022, 105, (19), pp. 195149
Issue Date:: 2022-05-15

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Field	Value	Language
dc.contributor.author	Scammell, HD
dc.contributor.author	Ingham, J
dc.contributor.author	Geier, M
dc.contributor.author	Li, T
dc.date.accessioned	2023-03-10T02:15:42Z
dc.date.available	2023-03-10T02:15:42Z
dc.date.issued	2022-05-15
dc.identifier.citation	Physical Review B, 2022, 105, (19), pp. 195149
dc.identifier.issn	2469-9950
dc.identifier.issn	2469-9969
dc.identifier.uri	http://hdl.handle.net/10453/166937
dc.description.abstract	We explore higher-order topological superconductivity in an artificial Dirac material with intrinsic spin-orbit coupling, which is a doped Z2 topological insulator in the normal state. A mechanism for superconductivity due to repulsive interactions, pseudospin pairing, has recently been shown to naturally result in higher-order topology in Dirac systems past a minimum chemical potential [T. Li et al., 2D Mater. 9, 015031 (2022)2053-158310.1088/2053-1583/ac4060]. Here we apply this theory through microscopic modeling of a superlattice potential imposed on an inversion-symmetric hole-doped semiconductor heterostructure, known as hole-based semiconductor artificial graphene, and extend previous work to include the effects of spin-orbit coupling. We find that spin-orbit coupling enhances interaction effects, providing an experimental handle to increase the efficiency of the superconducting mechanism. We show that the phase diagram of these systems, as a function of chemical potential and interaction strength, contains three superconducting states: a first-order topological p+ip state, a second-order topological spatially modulated p+iτp state, and a second-order topological extended s-wave state sτ. We calculate the symmetry-based indicators for the p+iτp and sτ states, which prove these states possess second-order topology. Exact diagonalization results are presented which illustrate the interplay between the boundary physics and spin-orbit interaction. We argue that this class of systems offers an experimental platform to engineer and explore first- and higher-order topological superconducting states.
dc.language	en
dc.publisher	American Physical Society (APS)
dc.relation.ispartof	Physical Review B
dc.relation.isbasedon	10.1103/PhysRevB.105.195149
dc.rights	info:eu-repo/semantics/closedAccess
dc.subject	02 Physical Sciences, 03 Chemical Sciences, 09 Engineering
dc.subject.classification	Fluids & Plasmas
dc.title	Intrinsic first- and higher-order topological superconductivity in a doped topological insulator
dc.type	Journal Article
utslib.citation.volume	105
utslib.for	02 Physical Sciences
utslib.for	03 Chemical Sciences
utslib.for	09 Engineering
pubs.organisational-group	/University of Technology Sydney
pubs.organisational-group	/University of Technology Sydney/Faculty of Science
pubs.organisational-group	/University of Technology Sydney/Faculty of Science/School of Mathematical and Physical Sciences
utslib.copyright.status	closed_access	*
dc.date.updated	2023-03-10T02:15:40Z
pubs.issue	19
pubs.publication-status	Published
pubs.volume	105
utslib.citation.issue	19

Abstract:

We explore higher-order topological superconductivity in an artificial Dirac material with intrinsic spin-orbit coupling, which is a doped Z2 topological insulator in the normal state. A mechanism for superconductivity due to repulsive interactions, pseudospin pairing, has recently been shown to naturally result in higher-order topology in Dirac systems past a minimum chemical potential [T. Li et al., 2D Mater. 9, 015031 (2022)2053-158310.1088/2053-1583/ac4060]. Here we apply this theory through microscopic modeling of a superlattice potential imposed on an inversion-symmetric hole-doped semiconductor heterostructure, known as hole-based semiconductor artificial graphene, and extend previous work to include the effects of spin-orbit coupling. We find that spin-orbit coupling enhances interaction effects, providing an experimental handle to increase the efficiency of the superconducting mechanism. We show that the phase diagram of these systems, as a function of chemical potential and interaction strength, contains three superconducting states: a first-order topological p+ip state, a second-order topological spatially modulated p+iτp state, and a second-order topological extended s-wave state sτ. We calculate the symmetry-based indicators for the p+iτp and sτ states, which prove these states possess second-order topology. Exact diagonalization results are presented which illustrate the interplay between the boundary physics and spin-orbit interaction. We argue that this class of systems offers an experimental platform to engineer and explore first- and higher-order topological superconducting states.

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http://hdl.handle.net/10453/166937