Journal ArticleDOI
Superconductivity and strong correlations in moiré flat bands
TLDR
In this article, the status and prospects for flat-band engineering in van der Waals heterostructures and explore how both phenomena emerge from the moire flat bands are reviewed and discussed.Abstract:
Strongly correlated systems can give rise to spectacular phenomenology, from high-temperature superconductivity to the emergence of states of matter characterized by long-range quantum entanglement. Low-density flat-band systems play a vital role because the energy range of the band is so narrow that the Coulomb interactions dominate over kinetic energy, putting these materials in the strongly-correlated regime. Experimentally, when a band is narrow in both energy and momentum, its filling may be tuned in situ across the whole range, from empty to full. Recently, one particular flat-band system—that of van der Waals heterostructures, such as twisted bilayer graphene—has exhibited strongly correlated states and superconductivity, but it is still not clear to what extent the two are linked. Here, we review the status and prospects for flat-band engineering in van der Waals heterostructures and explore how both phenomena emerge from the moire flat bands. The identification of superconductivity and strong interactions in twisted bilayer 2D materials prompted many questions about the interplay of these phenomena. This Perspective presents the status of the field and the urgent issues for future study.read more
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Journal ArticleDOI
Moiré heterostructures as a condensed-matter quantum simulator
Dante M. Kennes,Dante M. Kennes,Martin Claassen,Lede Xian,Antoine Georges,Andrew J. Millis,James Hone,Cory Dean,Dimitri Basov,Abhay Pasupathy,Angel Rubio +10 more
TL;DR: In this article, the authors explore the idea of adopting twisted van der Waals heterostructures as a quantum simulation platform that enables the study of strongly correlated physics and topology in quantum materials.
Journal Article
Origin of Mott Insulating Behavior and Superconductivity in Twisted Bilayer Graphene
TL;DR: In this article, a Mott insulator with intervalley coherence was proposed to break U(1) valley symmetry, and a mechanism that selects this order over the competing magnetically ordered states favored by the Hunds coupling was described.
Journal ArticleDOI
Electric field–tunable superconductivity in alternating-twist magic-angle trilayer graphene
Zeyu Hao,A. M. Zimmerman,Patrick J. Ledwith,Eslam Khalaf,Danial Haie Najafabadi,Kenji Watanabe,Takashi Taniguchi,Ashvin Vishwanath,Philip Kim +8 more
TL;DR: In this paper, a van der Waals (vdW) heterostructure was constructed with three graphene layers stacked with alternating twist angles ±θ at the average twist angle θ ~ 156°, a theoretically predicted "magic angle" for the formation of flat electron bands, and the authors observed displacement field-tunable superconductivity with a maximum critical temperature of 21 kelvin.
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 ArticleDOI
Phase transitions in 2D materials
Wenbin Li,Xiaofeng Qian,Ju Li +2 more
TL;DR: In this article, the authors discuss the thermodynamic and kinetic features of 2D phase transitions arising from dimensionality confinement, elasticity, electrostatics, defects and chemistry unique to 2D materials.
References
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Journal ArticleDOI
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Journal ArticleDOI
Two-Dimensional Magnetotransport in the Extreme Quantum Limit
TL;DR: The formation of a Wigner solid or charge-density-wave state with triangular symmetry is suggested as a possible explanation for the formation of the Hall plateau in magnetotransport of high-mobility, two-dimensional electrons as mentioned in this paper.