Magneto transport of pressure induced flatbands in large angle twisted bilayer graphene

Fuente: arXiv
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Main Authors: Mondal, Ayan, Sinha, Priyanka, Chittari, Bheema Lingam
Format: Preprint
Published: 2025
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author Mondal, Ayan
Sinha, Priyanka
Chittari, Bheema Lingam
author_facet Mondal, Ayan
Sinha, Priyanka
Chittari, Bheema Lingam
contents Twisted bilayer graphene (TBG) exhibits flat electronic bands at the so-called magic angle ($\sim 1.1^\circ$), leading to strong electron correlations and emergent quantum phases such as superconductivity and correlated insulating states. However, beyond the magic angle, the band structure generally remains dispersive, diminishing interaction-driven phenomena. In this work, we explore the equivalence between pressure-induced flatbands and the magic-angle flatband in large-angle TBG by systematically analyzing the role of interlayer coupling modifications under perpendicular pressure. We show that pressure-induced flatbands exhibit spatial localization similar to magic-angle TBG, with charge density concentrated in the AA-stacked regions. Furthermore, the Hall conductivity and magneto-transport properties under an external magnetic field reveal that these pressure-induced flatbands share key signatures with the quantum Hall response of magic-angle TBG. The obtained Hofstadter spectrum shows four consistent low-energy gaps across all twist angles under pressure, which align with the calculated Hall conductivity plateaus. Our findings suggest that pressure offers an alternative pathway to engineer flat electronic bands and correlated states in TBG, extending the landscape of tunable moiré materials beyond the constraints of the magic angle.
format Preprint
id arxiv_https___arxiv_org_abs_2503_22920
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Magneto transport of pressure induced flatbands in large angle twisted bilayer graphene
Mondal, Ayan
Sinha, Priyanka
Chittari, Bheema Lingam
Mesoscale and Nanoscale Physics
Materials Science
Twisted bilayer graphene (TBG) exhibits flat electronic bands at the so-called magic angle ($\sim 1.1^\circ$), leading to strong electron correlations and emergent quantum phases such as superconductivity and correlated insulating states. However, beyond the magic angle, the band structure generally remains dispersive, diminishing interaction-driven phenomena. In this work, we explore the equivalence between pressure-induced flatbands and the magic-angle flatband in large-angle TBG by systematically analyzing the role of interlayer coupling modifications under perpendicular pressure. We show that pressure-induced flatbands exhibit spatial localization similar to magic-angle TBG, with charge density concentrated in the AA-stacked regions. Furthermore, the Hall conductivity and magneto-transport properties under an external magnetic field reveal that these pressure-induced flatbands share key signatures with the quantum Hall response of magic-angle TBG. The obtained Hofstadter spectrum shows four consistent low-energy gaps across all twist angles under pressure, which align with the calculated Hall conductivity plateaus. Our findings suggest that pressure offers an alternative pathway to engineer flat electronic bands and correlated states in TBG, extending the landscape of tunable moiré materials beyond the constraints of the magic angle.
title Magneto transport of pressure induced flatbands in large angle twisted bilayer graphene
topic Mesoscale and Nanoscale Physics
Materials Science
url https://arxiv.org/abs/2503.22920