Electronic structure of topological materials probed by angle-resolved photoemission spectroscopy

The research in topological materials had been an extensive source for prediction and observation of new and exotic phenomena at the condensed matter level. During the last 20 years, a variety of new topological phases of matter had emerged. The most prominent are Topological Insulators and Weyl Sem...

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Detalles Bibliográficos
Autor: Pedro Henrique Rezende Gonçalves
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2021
País:Brasil
Institución:Universidade Federal de Minas Gerais (UFMG)
Repositorio:Repositório Institucional da UFMG
Idioma:inglés
OAI Identifier:oai:repositorio.ufmg.br:1843/38460
Acceso en línea:http://hdl.handle.net/1843/38460
https://orcid.org/ 0000-0001-6773-8921
Access Level:acceso abierto
Palabra clave:Topological insulators
Weyl semimetals
Charge-density waves
Angle-resolved photoemission spectroscopy
Estrutura eletrônica
Semimetais
Fotoemissão
Ondas de densidade de carga
Descripción
Sumario:The research in topological materials had been an extensive source for prediction and observation of new and exotic phenomena at the condensed matter level. During the last 20 years, a variety of new topological phases of matter had emerged. The most prominent are Topological Insulators and Weyl Semimetals. In this thesis, we used Angle-resolved Photoemission Spectroscopy to characterize the electronic structure of two topological materials: the quaternary topological insulator BiSbSe2.5Te0.5 and the topological Weyl semimetal candidate TaTe4. We reported the realization of a stable quaternary topological insulator, BiSbSe2.5Te0.5, characterized by a positive doping and charge carriers with smaller effective mass when compared with Bi2Se3. About TaTe4, we report a 2D Fermi surface composed by four Dirac/Weyl cones in the surface first Brillouin zone. The electronic structure of these metallic states is compatible with previous findings in the literature, showing a coexistence of CDW and topological features in a 2D Fermi surface.