t the Verge of Topology: Vacancy-Driven Quantum Spin Hall in Trivial Insulator

Autor(es)

de Lima, Felipe Crasto ^{[1, 2]} ; Fazzio, Adalberto ^{[1, 2]}

Afiliação do(s) autor(es)

^[1] CNPEM, Brazilian Nanotechnol Natl Lab, BR-13083970 Campinas, SP - Brazil

^[2] CNPEM, Ilum Sch Sci, BR-13083970 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Nano Letters; v. 21, n. 22, p. 9398-9402, NOV 24 2021.
• Citações Web of Science: 0

Resumo

Vacancies in materials structure-lowering its atomic density-take the system closer to the atomic limit, to which all systems are topologically trivial. Here we show a mechanism of mediated interaction between vacancies inducing a topologically nontrivial phase. Within an ab initio approach we explore topological transition dependence with the vacancy density in transition metal dichalcogenides. As a case of study, we focus on the PtSe2, for which the pristine form is a trivial semiconductor with an energy gap of 1.2 eV. The vacancies states lead to a large topological gap of 180 meV within the pristine system gap. We derive an effective model describing this topological phase in other transition metal dichalcogenide systems. The mechanism driving the topological phase allows the construction of backscattering protected metallic channels embedded in a semiconducting host. (AU)

• Processo FAPESP: 17/02317-2 - Interfaces em materiais: propriedades eletrônicas, magnéticas, estruturais e de transporte
• Beneficiário: Adalberto Fazzio
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 19/20857-0 - Materiais bidimensionais e fases topológicas: predição e controle de suas propriedades
• Beneficiário: Felipe David Crasto de Lima
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado