Electric field tunable bands in doubly aligned bilayer graphene hBN moire superlattice

Fuente: arXiv
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Autori principali: Tiwari, Priya, Watanabe, Kenji, Taniguchi, Takashi, Bid, Aveek
Natura: Preprint
Pubblicazione: 2025
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author Tiwari, Priya
Watanabe, Kenji
Taniguchi, Takashi
Bid, Aveek
author_facet Tiwari, Priya
Watanabe, Kenji
Taniguchi, Takashi
Bid, Aveek
contents In this letter, we demonstrate electric field-induced band modification of an asymmetrically twisted hBN/BLG/hBN supermoire lattice. Distinct from unaligned BLG/hBN systems, we observe regions in the density-displacement field (n-D) plane where the device conductance is independent of n and decreases as |D| increases. This distinction arises due to the angle asymmetry between the layers, which induces field-controlled layer polarization. We identify D-dependent additional band gaps near the charge neutrality point that appear in the conduction (valence) band for negative (positive) D values. In the quantum Hall regime, new 6-fold degenerate Landau levels are observed. Our findings establish that in an asymmetric supermoire heterostructure, an external vertical displacement field affects the valence and conduction bands very differently and sheds light on the asymmetric conductance patterns noted in previous studies.
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id arxiv_https___arxiv_org_abs_2502_03925
institution arXiv
publishDate 2025
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spellingShingle Electric field tunable bands in doubly aligned bilayer graphene hBN moire superlattice
Tiwari, Priya
Watanabe, Kenji
Taniguchi, Takashi
Bid, Aveek
Mesoscale and Nanoscale Physics
In this letter, we demonstrate electric field-induced band modification of an asymmetrically twisted hBN/BLG/hBN supermoire lattice. Distinct from unaligned BLG/hBN systems, we observe regions in the density-displacement field (n-D) plane where the device conductance is independent of n and decreases as |D| increases. This distinction arises due to the angle asymmetry between the layers, which induces field-controlled layer polarization. We identify D-dependent additional band gaps near the charge neutrality point that appear in the conduction (valence) band for negative (positive) D values. In the quantum Hall regime, new 6-fold degenerate Landau levels are observed. Our findings establish that in an asymmetric supermoire heterostructure, an external vertical displacement field affects the valence and conduction bands very differently and sheds light on the asymmetric conductance patterns noted in previous studies.
title Electric field tunable bands in doubly aligned bilayer graphene hBN moire superlattice
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2502.03925