2024/06/28 by Jin Jiang, Kenji Watanabe, Jiang, Jin +5
Engineering · Materials Science · #FOS: Physical sciences #Graphene and Nanomaterials Applications #Graphene research and applications #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Strongly Correlated Electrons (cond-mat.str-el)
paper · pdf · doi:10.48550/arxiv.2406.19915
openalex publication_date 2024/06/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
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.