Journal Club do Departamento de Física dos Materiais e Mecânica
Nesta semana o pós-graduando Oscar Andrés Babilonia Pérez, do Grupo Teórico de Materiais, comentará o artigo:
Prediction of Two-Dimensional Topological Crystalline Insulator in PbSe Monolayer
Two-dimensional (2D) topological crystalline insulator, a new class where states are protected by lattice symmetry instead of by time-reversal symmetry, is predicted in PbSe monolayer based on first-principles electronic structure calculations. A combination of strong spin−orbit interaction with quantum confinement effects in PbSe monolayer lead to a topological phase transition with an even number of band inversion momentum space points. We demonstrate that the PbSe nanostructure presents pairs of spin-polarized Dirac cones coming from the monolayer edges, where each Dirac pair presents a unique spin alignment, leading to a quantum spin Hall system. More importantly, due to the quantum confinement this 2D nanostructure presents larger band gap as compared to its parent narrow band gap trivial insulator bulk PbSe, favoring a room-temperature 2D band gap with crystalline-protected Dirac states at the edges, turning this system interesting to combine nontrivial topologic!
al states with nanoelectronic and spintronic applications.
Link: http://pubs.acs.org/doi/abs/10.1021/nl502481f
Data: 12 de maio de 2015 (terça-feira)
Horário: às 12h10min
Local: Sala de Seminários José Roberto Leite - Ed. Alessandro Volta (bloco C) - sala 110
Visite a página do Journal Club do FMT:
http://portal.if.usp.br/fmt/pt-br/node/631
