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Related papers: Optically induced flat bands in twisted bilayer gr…

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Twisted bilayer graphene has been argued theoretically to host exceptionally flat bands when the angle between the two layers falls within a magic range near 1.1$^\circ$. This is now strongly supported by experiment, which furthermore…

Strongly Correlated Electrons · Physics 2019-07-24 Kasra Hejazi , Chunxiao Liu , Leon Balents

We use a lowest Landau level model to study the recent observation of an anomalous Hall effect in twisted bilayer graphene. This effective model is rooted in the occurrence of Chern bands which arise due to the coupling between the graphene…

Strongly Correlated Electrons · Physics 2020-04-28 Nick Bultinck , Shubhayu Chatterjee , Michael P. Zaletel

The existence of Bloch flat bands provides an facile pathway to realize strongly correlated phenomena in materials. Using density-functional theory and tight-binding approach, we show that the flat bands can form in twisted bilayer of…

Materials Science · Physics 2020-03-04 Xing-Ju Zhao , Yang Yang , Dong-Bo Zhang , Su-Huai Wei

Stacked graphene multilayers with a small relative twist angle between each of the layers have been found to host flat bands at a series of magic angles. We consider the effect that Dirac point asymmetry between the layers, and in…

Mesoscale and Nanoscale Physics · Physics 2024-12-31 Adam Eaton , Yantao Li , Herbert Fertig , Babak Seradjeh

A striking series of experiments have observed superconductivity in Bernal-stacked bilayer graphene (BBG) when the energy bands are flattened by applying an electrical displacement field. Intriguingly, superconductivity manifests only at…

Superconductivity · Physics 2025-02-03 Glenn Wagner , Yves H. Kwan , Nick Bultinck , Steven H. Simon , S. A. Parameswaran

We report on the observation of photogalvanic effects in twisted bilayer graphene (tBLG) with a twist angle of 0.6{\deg}. We show that excitation of tBLG bulk causes a photocurrent, whose sign and magnitude are controlled by orientation of…

Mesoscale and Nanoscale Physics · Physics 2020-12-02 M. Otteneder , S. Hubmann , X. Lu , D. Kozlov , L. E. Golub , K. Watanabe , T. Taniguchi , D. K. Efetov , S. D. Ganichev

Recent transport studies have demonstrated the great potential of twisted monolayer-bilayer graphene (tMBG) as a new platform to host moir\'e flat bands with a higher tunability than twisted bilayer graphene (tBG). However, a direct…

Mesoscale and Nanoscale Physics · Physics 2024-01-10 Ling-Hui Tong , Qingjun Tong , Li-Zhen Yang , Yue-Ying Zhou , Qilong Wu , Yuan Tian , Li Zhang , Lijie Zhang , Zhihui Qin , Long-Jing Yin

Using scanning probe microscopy and spectroscopy, we explore the spatial symmetry of the electronic wavefunctions of twisted bilayer graphene at the "magic angle" of 1.1 degrees. This small twist angle leads to a long wavelength moir\'e…

Mesoscale and Nanoscale Physics · Physics 2020-08-12 Zhiming Zhang , Rachel Myers , Kenji Watanabe , Takashi Taniguchi , Brian J. LeRoy

We present a tight-binding calculation of a twisted bilayer graphene at magic angle $\theta\sim 1.08^\circ$, allowing for full, in- and out-of-plane, relaxation of the atomic positions. The resulting band structure displays as usual four…

Strongly Correlated Electrons · Physics 2018-12-19 M. Angeli , D. Mandelli , A. Valli , A. Amaricci , M. Capone , E. Tosatti , M. Fabrizio

Twisted two-dimensional structures open new possibilities in band structure engineering. At magic twist angles, flat bands emerge, which give a new drive to the field of strongly correlated physics. In twisted double bilayer graphene dual…

In graphene, charged defects break the electron-hole symmetry and can even give rise to exotic collapse states when the defect charge exceeds a critical value which is proportional to the Fermi velocity. In this work, we investigate the…

We present a theoretical study of the local optical conductivity, plasmon spectra, and thermoelectric properties of twisted bilayer graphene (TBG) at different filling factors and twist angles $\theta$. Our calculations are based on the…

Mesoscale and Nanoscale Physics · Physics 2020-09-04 Pietro Novelli , Iacopo Torre , Frank H. L. Koppens , Fabio Taddei , Marco Polini

Moir\'{e} superlattices in twisted bilayer graphene and transition-metal dichalcogenides have emerged as a powerful tool for engineering novel band structures and quantum phases of two-dimensional quantum materials. Here we investigate…

Quantum Gases · Physics 2021-03-17 Xi-Wang Luo , Chuanwei Zhang

We theoretically study the effects of electron-electron interaction in twisted bilayer graphene in applied transverse dc electric field. When the twist angle is not very small, the electronic spectrum of the bilayer consists of four Dirac…

Strongly Correlated Electrons · Physics 2018-07-04 A. O. Sboychakov , A. V. Rozhkov , A. L. Rakhmanov , Franco Nori

We investigate the effect of a magnetic field on the band structure of bilayer graphene with a magic twist angle of 1.08{\deg}. The coupling of a tight-binding model and the Peierls phase allows the calculation of the energy bands of…

Mesoscale and Nanoscale Physics · Physics 2024-05-20 Gaëlle Bigeard , Alessandro Cresti

Electronic correlations in two-dimensional materials play a crucial role in stabilising emergent phases of matter. The realisation of correlation-driven phenomena in graphene has remained a longstanding goal, primarily due to the absence of…

Mesoscale and Nanoscale Physics · Physics 2023-09-19 Saisab Bhowmik , Arindam Ghosh , U. Chandni

Twisted bilayer graphene (tBLG) has recently emerged as a new platform for studying electron correlations, the strength of which can be controlled via the twist angle. Here, we study the effect of internal screening on electron-electron…

Strongly Correlated Electrons · Physics 2019-12-18 Zachary A. H. Goodwin , Fabiano Corsetti , Arash A. Mostofi , Johannes Lischner

We present a theoretical study of the intrinsic plasmonic properties of twisted bilayer graphene (TBG) as a function of the twist angle $\theta$ (and other microscopic parameters such as temperature and filling factor). Our calculations,…

Mesoscale and Nanoscale Physics · Physics 2024-09-06 Lorenzo Cavicchi , Iacopo Torre , Pablo Jarillo-Herrero , Frank H. L. Koppens , Marco Polini

Emergent quantum phases driven by electronic interactions can manifest in materials with narrowly dispersing, i.e. "flat", energy bands. Recently, flat bands have been realized in a variety of graphene-based heterostructures using the…

Close to a magical angle, twisted bilayer graphene (TBLG) systems exhibit isolated flat electronic bands and, accordingly, strong electron localization. TBLGs have hence been ideal platforms to explore superconductivity, correlated…

Mesoscale and Nanoscale Physics · Physics 2021-05-28 V. Hung Nguyen , D. Paszko , M. Lamparski , B. Van Troeye , V. Meunier , J. -C. Charlier