Band structure of twisted bilayer graphene on hexagonal boron nitride
Reads0
Chats0
TLDR
In this article, the effect of hexagonal boron nitride (hBN) layer closely aligned with twisted bilayer graphene (TBG) was studied. And they found that for a realistic combination of the twist angle in the TBG and the twisted angle between the hBN and the graphene layer, the system can be described using a single moir\'e unit cell.Abstract:
The effect of a hexagonal boron nitride (hBN) layer closely aligned with twisted bilayer graphene (TBG) is studied. At sufficiently low angles between twisted bilayer graphene and hBN, ${\ensuremath{\theta}}_{hBN}\ensuremath{\lesssim}{2}^{\ensuremath{\circ}}$, the graphene electronic structure is strongly disturbed. The width of the low-energy peak in the density of states changes from $W\ensuremath{\sim}5--10$ meV for a decoupled system to $\ensuremath{\sim}20--30$ meV. Spikes in the density of states due to van Hove singularities are smoothed out. We find that for a realistic combination of the twist angle in the TBG and the twist angle between the hBN and the graphene layer the system can be described using a single moir\'e unit cell.read more
Citations
More filters
Journal Article
Intrinsic Quantized Anomalous Hall Effect in a Moiré Heterostructure, Part III: Scanning Probe Magnetometry
Charles Tschirhart,Marec Serlin,Hryhoriy Polshyn,Yuxuan Zhang,Jiacheng Zhu,Leon Balents,Martin E. Huber,Kenji Watanabe,Takashi Taniguchi,Andrea Young +9 more
TL;DR: The quantum anomalous Hall (QAH) effect combines topology and magnetism to produce precisely quantized Hall resistance at zero magnetic field as discussed by the authors, which is driven by intrinsic strong interactions, which polarize the electrons into a single spin and valley-resolved moiré miniband with Chern number C = 1.
Journal Article
Charge order and broken rotational symmetry in magic-angle twisted bilayer graphene
TL;DR: When scanning tunnelling spectroscopy is used to map the electronic structure of magic-angle twisted bilayer graphene, a pseudogap phase is found, accompanied by a global charge-ordered stripe phase, which provides new evidence of a deeper link underlying the phenomenology of these systems.
Journal Article
Detecting topological currents in graphene superlattices
Geliang Yu,Andrey V. Kretinin,Justin C. W. Song,Roman V. Gorbachev,Leonid Levitov,Konstantin S. Novoselov,Andre K. Geim +6 more
TL;DR: The authors measured the transport characteristics of the sample, which were consistent with the theoretical predictions for the VHE, and observed the long-range character of topological currents and their transistor-like control by means of gate voltage can be exploited for information processing based on valley degrees of freedom.
Journal ArticleDOI
Moiré commensurability and the quantum anomalous Hall effect in twisted bilayer graphene on hexagonal boron nitride
TL;DR: The quantum anomalous Hall effect occurs in twisted bilayer graphene when it is nearly aligned with an encapsulating hexagonal boron nitride (hBN) layer as discussed by the authors.
Journal ArticleDOI
Chern mosaic and Berry-curvature magnetism in magic-angle graphene
Sameer Grover,Matan Bocarsly,Aviram Uri,Petr Stepanov,G. D. Battista,Indranil Roy,Jiewen Xiao,Alexander Y. Meltzer,Yuri Myasoedov,Keshav Pareek,Kenji Watanabe,Takashi Taniguchi,Binghai Yan,Ady Stern,Erez Berg,Dmitri K. Efetov,Eli Zeldov +16 more
TL;DR: In this paper , a SQUID-on-tip was used to directly image the nanoscale Berry-curvature-induced equilibrium orbital magnetism, the polarity of which is governed by the local Chern number, and detect its two constituent components associated with the drift and the self-rotation of the electronic wave packets.
References
More filters
Journal ArticleDOI
Unconventional superconductivity in magic-angle graphene superlattices
Yuan Cao,Valla Fatemi,Shiang Fang,Kenji Watanabe,Takashi Taniguchi,Efthimios Kaxiras,Pablo Jarillo-Herrero +6 more
TL;DR: The realization of intrinsic unconventional superconductivity is reported—which cannot be explained by weak electron–phonon interactions—in a two-dimensional superlattice created by stacking two sheets of graphene that are twisted relative to each other by a small angle.
Journal ArticleDOI
Correlated insulator behaviour at half-filling in magic-angle graphene superlattices
Yuan Cao,Valla Fatemi,Ahmet Demir,Shiang Fang,Spencer Tomarken,Jason Luo,Javier Sanchez-Yamagishi,Kenji Watanabe,Takashi Taniguchi,Efthimios Kaxiras,Raymond Ashoori,Pablo Jarillo-Herrero +11 more
TL;DR: It is shown experimentally that when this angle is close to the ‘magic’ angle the electronic band structure near zero Fermi energy becomes flat, owing to strong interlayer coupling, and these flat bands exhibit insulating states at half-filling, which are not expected in the absence of correlations between electrons.
Journal ArticleDOI
Moiré bands in twisted double-layer graphene
TL;DR: This work addresses the electronic structure of a twisted two-layer graphene system, showing that in its continuum Dirac model the moiré pattern periodicity leads to moirÉ Bloch bands.
Journal Article
Correlated Insulator Behaviour at Half-Filling in Magic Angle Graphene Superlattices
Yuan Cao,Valla Fatemi,Ahmet Demir,Shiang Fang,Spencer Tomarken,Jason Luo,Javier Sanchez-Yamagishi,Kenji Watanabe,Takashi Taniguchi,Efthimios Kaxiras,Raymond Ashoori,Pablo Jarillo-Herrero +11 more
TL;DR: In this article, the effects of the twist angle between different layers in a van der Waals heterostructure have been investigated and it was shown that when this angle is close to the magic angle, the electronic band structure near zero Fermi energy becomes flat, owing to strong interlayer coupling.
Journal ArticleDOI
Tuning superconductivity in twisted bilayer graphene.
Matthew Yankowitz,Shaowen Chen,Hryhoriy Polshyn,Yuxuan Zhang,Kenji Watanabe,Takashi Taniguchi,David Graf,Andrea Young,Cory Dean +8 more
TL;DR: This study demonstrates twisted bilayer graphene to be a distinctively tunable platform for exploring correlated states by inducing superconductivity at a twist angle larger than 1.1°—in which correlated phases are otherwise absent—by varying the interlayer spacing with hydrostatic pressure.