Correlated insulators in twisted mono-mono-bilayer graphene

Fuente: arXiv
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Hauptverfasser: Jiang, Jin, Watanabe, Kenji, Taniguchi, Takashi, Banerjee, Mitali
Format: Preprint
Veröffentlicht: 2024
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author Jiang, Jin
Watanabe, Kenji
Taniguchi, Takashi
Banerjee, Mitali
author_facet Jiang, Jin
Watanabe, Kenji
Taniguchi, Takashi
Banerjee, Mitali
contents Graphene-based moiré superlattice featuring flat bands is a promising platform for studying strongly correlated states. By tuning two twist angles and displacement fields in twisted mono-mono-bilayer graphene (TMMBG), we observed a correlated metallic state evolved into a valley-polarized correlated insulator at the filling factor of $ν= -2$, with the coupling strength between the top two monolayer graphene intensifying. Moreover, the corresponding effective g-factor obtained from fitting the thermal activation gap is enhanced with the coupling strength, suggesting that TMMBG can be harnessed for developing valleytronics devices. In addition, the observation of an unconventional correlated electron-hole insulator suggests that this state might be a candidate for an excitonic insulator, which may generated by the correlation from band nesting, which encourages further research in non-Fermi liquid physics. Our work reveals that tuning multiple twist angles can provide a unique route for studying quantum many-body states in twistronics.
format Preprint
id arxiv_https___arxiv_org_abs_2406_19915
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Correlated insulators in twisted mono-mono-bilayer graphene
Jiang, Jin
Watanabe, Kenji
Taniguchi, Takashi
Banerjee, Mitali
Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
Graphene-based moiré superlattice featuring flat bands is a promising platform for studying strongly correlated states. By tuning two twist angles and displacement fields in twisted mono-mono-bilayer graphene (TMMBG), we observed a correlated metallic state evolved into a valley-polarized correlated insulator at the filling factor of $ν= -2$, with the coupling strength between the top two monolayer graphene intensifying. Moreover, the corresponding effective g-factor obtained from fitting the thermal activation gap is enhanced with the coupling strength, suggesting that TMMBG can be harnessed for developing valleytronics devices. In addition, the observation of an unconventional correlated electron-hole insulator suggests that this state might be a candidate for an excitonic insulator, which may generated by the correlation from band nesting, which encourages further research in non-Fermi liquid physics. Our work reveals that tuning multiple twist angles can provide a unique route for studying quantum many-body states in twistronics.
title Correlated insulators in twisted mono-mono-bilayer graphene
topic Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
url https://arxiv.org/abs/2406.19915