Multiflat Bands and Strong Correlations in Twisted Bilayer BoronNitride: Doping-Induced Correlated Insulator and Superconductor

Two-dimensional materials, obtained by van der Waals stacking of layers, are fascinating objects of contemporary condensed matter research, exhibiting a variety of new physics. Inspired by the breakthroughs of twisted bilayer graphene (TBG), we demonstrate that twisted bilayer boron nitride (TBBN) i...

Descripción completa

Detalles Bibliográficos
Autores: Xian, Lede, Kennes, Dante M., Tancogne-Dejean, Nicolas, Altarelli, Massimo, Rubio Secades, Angel
Tipo de recurso: artículo
Fecha de publicación:2019
País:España
Institución:Universidad del País Vasco
Repositorio:Addi. Archivo Digital para la Docencia y la Investigación
OAI Identifier:oai:addi.ehu.eus:10810/39127
Acceso en línea:http://hdl.handle.net/10810/39127
Access Level:acceso abierto
Palabra clave:twisted bilayer
multiflat bands
strong correlations
Mott insulator
topological superconductor
ab initio calculation
graphene
excitons
Descripción
Sumario:Two-dimensional materials, obtained by van der Waals stacking of layers, are fascinating objects of contemporary condensed matter research, exhibiting a variety of new physics. Inspired by the breakthroughs of twisted bilayer graphene (TBG), we demonstrate that twisted bilayer boron nitride (TBBN) is an even more exciting novel system that turns out to be an excellent platform to realize new correlated phases and phenomena; exploration of its electronic properties shows that in contrast to TBG in TBBN multiple families of 2,4, and 6 -fold degenerate flat bands emerge without the need to fine tune close to a "magic angle", resulting in dramatic and tunable changes in optical properties and exciton physics, and providing an additional platform to study strong correlations. Upon doping, unforeseen new correlated phases of matter (insulating and superconducting) emerge. TBBN could thus provide a promising experimental platform, insensitive to small deviations in the twist angle, to study novel exciton condensate and spatial confinement physics, and correlations in two dimensions.