Nearly flat Chern band in periodically strained monolayer and bilayer graphene

Abstract

The flat band is a key ingredient for the realization of interesting quantum states for novel functionalities. In this work, we investigate the conditions for the flat band in both monolayer and bilayer graphene under periodic strain. We find topological nearly flat bands with homogeneous distribution of Berry curvature in both systems. The quantum metric of the nearly flat band closely resembles that for Landau levels. For monolayer graphene, the strain field can be regarded as an effective gauge field, while for Bernal-stacked (AB-stacked) bilayer graphene, its role is beyond the description of gauge field. We also provide an understanding of the origin of the nearly flat band in monolayer graphene in terms of the Jackiw-Rebbi model for Dirac fermions with sign-changing mass. Our work suggests strained graphene as a promising platform for strongly correlated quantum states.

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Cited by in corpus (10)

• Theory of Generalized Landau Levels and Implication for non-Abelian States
• Higher vortexability: zero field realization of higher Landau levels
• Contrasting twisted bilayer graphene and transition metal dichalcogenides for fractional Chern insulators: an emergent gauge picture
• Supersymmetry dictated topology in periodic gauge fields and realization in strained and twisted 2D materials
• Artificial moiré engineering for an ideal BHZ model
• Symmetry-based classification of exact flat bands in single and bilayer moiré systems
• Geometric transport signatures of strained multi-Weyl semimetals
• Protected Fermionic Zero Modes in Periodic Gauge Fields
• Unconventional Fractional Phases in Multi-Band Vortexable Systems
• Interaction-driven charge textures and unconventional superconductivity in strained monolayer graphene