English
Related papers

Related papers: Twist-angle dependence of electron correlations in…

200 papers

At certain angles of rotation called `magic angles' twisted bilayer graphene features almost flat bands. The resulting strong correlations drive the system to novel phases which have been observed in experiments recently. A complete…

Mesoscale and Nanoscale Physics · Physics 2018-11-01 Steven C. Carter , Hridis K. Pal , M. Kindermann

Recent experiments on magic-angle twisted bilayer graphene have discovered correlated insulating behavior and superconductivity at a fractional filling of an isolated narrow band. In this paper we show that magic-angle bilayer graphene…

Bilayer graphene twisted by a small angle shows a significant charge modulation away from neutrality, as the charge in the narrow bands near the Dirac point is mostly localized in the regions of the Moir\'e pattern with $AA$ stacking. The…

Mesoscale and Nanoscale Physics · Physics 2018-12-13 Francisco Guinea , Niels R. Walet

The symmetry-broken correlated states in twisted double bilayer graphene (TDBG) can be tuned via several external knobs, including twist angle, displacement field, and carrier density. However, a direct, momentum-resolved characterization…

Superlattices from twisted graphene mono- and bi-layer systems give rise to on-demand many-body states such as Mott insulators and unconventional superconductors. These phenomena are ascribed to a combination of flat bands and strong…

We present a theoretical investigation of the magnetic properties exhibited by twisted bilayer graphene (TBG) systems with small twist angles, where the appearance of flat minibands strongly enhances electron-electron interaction effects.…

Mesoscale and Nanoscale Physics · Physics 2025-04-08 Kevin J. U. Vidarte , Felipe Pérez Riffo , Eric Suárez Morell , Caio Lewenkopf

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

The salient property of the electronic band structure of twisted bilayer graphene (TBG), at the so-called magic angle (MA), is the emergence of flat bands around the charge neutrality point. These bands are associated with the observed…

Mesoscale and Nanoscale Physics · Physics 2023-09-04 Sonia Haddad , Takeo Kato , Jihang Zhu , Lassaad Mandhour

We identify states favored by Coulomb interactions projected onto the Wannier basis of the four narrow bands of the "magic angle" twisted bilayer graphene. At the filling of two electrons/holes per moire unit cell, such interactions favor…

Strongly Correlated Electrons · Physics 2019-06-20 Jian Kang , Oskar Vafek

The effects of the long range electrostatic interaction in twisted bilayer graphene are described using the Hartree-Fock approximation. The results show a significant dependence of the band widths and shapes on electron filling, and the…

Mesoscale and Nanoscale Physics · Physics 2022-07-29 Tommaso Cea , Pierre A. Pantaleón , Niels R. Walet , Francisco Guinea

We study the localization properties of electrons in incommensurate twisted bilayer graphene for small angles, encompassing the narrow-band regime, by numerically exact means. Sub-ballistic states are found within the narrow-band region…

Mesoscale and Nanoscale Physics · Physics 2022-03-08 Miguel Gonçalves , Hadi Z. Olyaei , Bruno Amorim , Rubem Mondaini , Pedro Ribeiro , Eduardo V. Castro

Magic-angle twisted bilayer graphene is the best studied physical platform featuring moire potential induced narrow bands with non-trivial topology and strong electronic correlations. Despite their significance, the Chern insulating states…

Mesoscale and Nanoscale Physics · Physics 2024-06-11 Xiaoyu Wang , Oskar Vafek

We study conductance across a twisted bilayer graphene coupled to single-layer graphene leads in two setups: a flake of graphene on top of an infinite graphene ribbon and two overlapping semi-infinite graphene ribbons. We find conductance…

Mesoscale and Nanoscale Physics · Physics 2020-07-30 Hadi Z. Olyaei , Bruno Amorim , Pedro Ribeiro , Eduardo V. Castro

Moir\'e materials, and in particular twisted bilayer graphene (TBG), exhibit a range of fascinating phenomena, that emerge from the interplay of band topology and interactions. We show that the non-linear second-order photoresponse is an…

Mesoscale and Nanoscale Physics · Physics 2021-07-21 Swati Chaudhary , Cyprian Lewandowski , Gil Refael

Since the discovery of superconductivity and correlated insulator at fractional electron fillings in the twisted bilayer graphene, most theoretical efforts have been focused on describing this system in terms of an effective extended…

Strongly Correlated Electrons · Physics 2019-04-24 Xiao-Chuan Wu , Chao-Ming Jian , Cenke Xu

Low-energy moir\'e flat bands in magic-angle twisted bilayer graphene (tBG) have demonstrated incredible potentials to exhibit rich exotic quantum phenomena. Theoretically, the moir\'e flat bands of tBG are based on the extended structures,…

Mesoscale and Nanoscale Physics · Physics 2022-05-23 Long-Jing Yin , Ling-Hui Tong , Yue-Ying Zhou , Yang Zhang , Yuan Tian , Li Zhang , Lijie Zhang , Zhihui Qin

Twisted bilayer graphene (TBG) exhibits flat electronic bands at the so-called magic angle ($\sim 1.1^\circ$), leading to strong electron correlations and emergent quantum phases such as superconductivity and correlated insulating states.…

Mesoscale and Nanoscale Physics · Physics 2025-04-01 Ayan Mondal , Priyanka Sinha , Bheema Lingam Chittari

Tailoring the interlayer twist angle of bilayer graphene (BLG) has a significant influence on its electronic properties, including superconductivity, topological transitions, ferromagnetic states and correlated insulating states. These…

Staking layered materials revealed to be a very powerful method to tailor their electronic properties. It has indeed been theoretically and experimentally shown that twisted bilayers of graphene (tBLG) with a rotation angle $\theta$,…

Mesoscale and Nanoscale Physics · Physics 2020-07-01 Omid Faizy Namarvar , Ahmed Missaoui , Laurence Magaud , Didier Mayou , Guy Trambly de Laissardière

We analyze the electronic structure of twisted bilayer graphene (TBG) nanoribbons close to the magic angle. We describe a transition from an incomplete to a complete moir\'e structure. By considering zigzag and armchair edge terminations,…

Mesoscale and Nanoscale Physics · Physics 2023-09-14 Elias Andrade , Pierre A. Pantaleón , Francisco Guinea , Gerardo G. Naumis