Gate-Tunable Topological Flat Bands in Trilayer Graphene Boron-Nitride Moiré Superlattices

Bheema Lingam Chittari; Guorui Chen; Yuanbo Zhang; Feng Wang; Jeil Jung

doi:10.1103/PhysRevLett.122.016401

Gate-Tunable Topological Flat Bands in Trilayer Graphene Boron-Nitride Moiré Superlattices

Bheema Lingam Chittari, Guorui Chen, Yuanbo Zhang, Feng Wang, Jeil Jung

Department of Physics

Research output: Contribution to journal › Article › peer-review

136 Scopus citations

Abstract

We investigate the electronic structure of the flat bands induced by moiré superlattices and electric fields in nearly aligned ABC trilayer graphene (TLG) boron-nitride (BN) interfaces where Coulomb effects can lead to correlated gapped phases. Our calculations indicate that valley-spin resolved isolated superlattice flat bands that carry a finite Chern number C=3 proportional to the layer number can appear near charge neutrality for appropriate perpendicular electric fields and twist angles. When the degeneracy of the bands is lifted by Coulomb interactions, these topological bands can lead to anomalous quantum Hall phases that embody orbital and spin magnetism. Narrow bandwidths of ∼10 meV achievable for a continuous range of twist angles θ0.6° with moderate interlayer potential differences of ∼50 meV make the TLG-BN systems a promising platform for the study of electric-field tunable Coulomb-interaction-driven spontaneous Hall phases.

Original language	English
Article number	016401
Journal	Physical Review Letters
Volume	122
Issue number	1
DOIs	https://doi.org/10.1103/PhysRevLett.122.016401
State	Published - 3 Jan 2019

Access to Document

10.1103/PhysRevLett.122.016401

Cite this

@article{82682f3c8d2f4ecbb4e00a3d588bfff1,

title = "Gate-Tunable Topological Flat Bands in Trilayer Graphene Boron-Nitride Moir{\'e} Superlattices",

abstract = "We investigate the electronic structure of the flat bands induced by moir{\'e} superlattices and electric fields in nearly aligned ABC trilayer graphene (TLG) boron-nitride (BN) interfaces where Coulomb effects can lead to correlated gapped phases. Our calculations indicate that valley-spin resolved isolated superlattice flat bands that carry a finite Chern number C=3 proportional to the layer number can appear near charge neutrality for appropriate perpendicular electric fields and twist angles. When the degeneracy of the bands is lifted by Coulomb interactions, these topological bands can lead to anomalous quantum Hall phases that embody orbital and spin magnetism. Narrow bandwidths of ∼10 meV achievable for a continuous range of twist angles θ0.6° with moderate interlayer potential differences of ∼50 meV make the TLG-BN systems a promising platform for the study of electric-field tunable Coulomb-interaction-driven spontaneous Hall phases.",

author = "Chittari, {Bheema Lingam} and Guorui Chen and Yuanbo Zhang and Feng Wang and Jeil Jung",

note = "Publisher Copyright: {\textcopyright} 2019 American Physical Society.",

year = "2019",

month = jan,

day = "3",

doi = "10.1103/PhysRevLett.122.016401",

language = "English",

volume = "122",

journal = "Physical Review Letters",

issn = "0031-9007",

publisher = "American Physical Society",

number = "1",

}

TY - JOUR

T1 - Gate-Tunable Topological Flat Bands in Trilayer Graphene Boron-Nitride Moiré Superlattices

AU - Chittari, Bheema Lingam

AU - Chen, Guorui

AU - Zhang, Yuanbo

AU - Wang, Feng

AU - Jung, Jeil

PY - 2019/1/3

Y1 - 2019/1/3

N2 - We investigate the electronic structure of the flat bands induced by moiré superlattices and electric fields in nearly aligned ABC trilayer graphene (TLG) boron-nitride (BN) interfaces where Coulomb effects can lead to correlated gapped phases. Our calculations indicate that valley-spin resolved isolated superlattice flat bands that carry a finite Chern number C=3 proportional to the layer number can appear near charge neutrality for appropriate perpendicular electric fields and twist angles. When the degeneracy of the bands is lifted by Coulomb interactions, these topological bands can lead to anomalous quantum Hall phases that embody orbital and spin magnetism. Narrow bandwidths of ∼10 meV achievable for a continuous range of twist angles θ0.6° with moderate interlayer potential differences of ∼50 meV make the TLG-BN systems a promising platform for the study of electric-field tunable Coulomb-interaction-driven spontaneous Hall phases.

AB - We investigate the electronic structure of the flat bands induced by moiré superlattices and electric fields in nearly aligned ABC trilayer graphene (TLG) boron-nitride (BN) interfaces where Coulomb effects can lead to correlated gapped phases. Our calculations indicate that valley-spin resolved isolated superlattice flat bands that carry a finite Chern number C=3 proportional to the layer number can appear near charge neutrality for appropriate perpendicular electric fields and twist angles. When the degeneracy of the bands is lifted by Coulomb interactions, these topological bands can lead to anomalous quantum Hall phases that embody orbital and spin magnetism. Narrow bandwidths of ∼10 meV achievable for a continuous range of twist angles θ0.6° with moderate interlayer potential differences of ∼50 meV make the TLG-BN systems a promising platform for the study of electric-field tunable Coulomb-interaction-driven spontaneous Hall phases.

UR - http://www.scopus.com/inward/record.url?scp=85059843744&partnerID=8YFLogxK

U2 - 10.1103/PhysRevLett.122.016401

DO - 10.1103/PhysRevLett.122.016401

M3 - Article

C2 - 31012684

AN - SCOPUS:85059843744

SN - 0031-9007

VL - 122

JO - Physical Review Letters

JF - Physical Review Letters

IS - 1

M1 - 016401

ER -

Gate-Tunable Topological Flat Bands in Trilayer Graphene Boron-Nitride Moiré Superlattices

Abstract

Access to Document

Other files and links

Fingerprint

Cite this