Irradiated graphene as a tunable Floquet topological insulator

In the presence of a circularly polarized mid-infrared radiation graphene develops dynamical band gaps in itsquasi-energy band structure and becomes a Floquet insulator. Here we analyze how topologically protected edgestates arise inside these gaps in the presence of an edge. Our results show that t...

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Detalles Bibliográficos
Autores: Usaj, Gonzalo, Pérez Piskunow, Pablo Matías, Foa Torres, Luis Eduardo Francisco, Balseiro, Carlos Antonio
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2014
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/31852
Acceso en línea:http://hdl.handle.net/11336/31852
Access Level:acceso abierto
Palabra clave:graphene
topological insulators
chern numbers
floquet
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
Descripción
Sumario:In the presence of a circularly polarized mid-infrared radiation graphene develops dynamical band gaps in itsquasi-energy band structure and becomes a Floquet insulator. Here we analyze how topologically protected edgestates arise inside these gaps in the presence of an edge. Our results show that the gap appearing at̵hΩ~2, where̵hΩis the photon energy, is bridged by two chiral edge states whose propagation direction is set by the directionof the polarization of the radiation field. Therefore, both the propagation direction and the energy window wherethe states appear can be controlled externally. We present both analytical and numerical calculations that fullycharacterize these states. This is complemented by simple topological arguments that account for them and bynumerical calculations for the case of semi-infinite sample, thereby eliminating finite size effects.