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Related papers: Soft modes in magic angle twisted bilayer graphene

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Superconductivity often occurs close to broken-symmetry parent states and is especially common in doped magnetic insulators. When twisted close to a magic relative orientation angle near 1 degree, bilayer graphene has flat moire…

Twisted bilayer graphene offers a unique bilayer two-dimensional-electron system where the layer separation is only in sub-nanometer scale. Unlike Bernal-stacked bilayer, the layer degree of freedom is disentangled from spin and valley,…

Twisted bilayer graphene (TBG) is known for exhibiting highly correlated phases at magic angles due to the emergence of flat bands that enhance electron-electron interactions. In the TBG chiral model, electronic wave function properties…

Mesoscale and Nanoscale Physics · Physics 2023-09-15 Leonardo A. Navarro-Labastida , Gerardo G. Naumis

Twisted bilayer graphene (TBG) develops large moir\'e patterns at small twist angles with flat energy bands hosting domes of superconductivity. The large system size and intricate band structure have however hampered investigations into the…

Superconductivity · Physics 2022-07-19 Tomas Löthman , Johann Schmidt , Fariborz Parhizgar , Annica M. Black-Schaffer

Magic angle twisted bilayer graphene has emerged as a powerful platform for studying strongly correlated electron physics, owing to its almost dispersionless low-energy bands and the ability to tune the band filling by electrostatic gating.…

Mesoscale and Nanoscale Physics · Physics 2021-07-21 Nikhil Tilak , Xinyuan Lai , Shuang Wu , Zhenyuan Zhang , Mingyu Xu , Raquel de Almeida Ribeiro , Paul C Canfield , Eva Y. Andrei

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 non-interacting energy spectrum of graphene and its bilayer counterpart consists of multiple degeneracies owing to the inherent spin, valley and layer symmetries. Interactions among charge carriers are expected to spontaneously break…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 R. Thomas Weitz , Monica T. Allen , Benjamin E. Feldman , Jens Martin , Amir Yacoby

Two new Raman modes below 100 cm^-1 are observed in twisted bilayer graphene grown by chemical vapor deposition. The two modes are observed in a small range of twisting angle at which the intensity of the G Raman peak is strongly enhanced,…

Mesoscale and Nanoscale Physics · Physics 2013-08-16 Rui He , Ting-Fung Chung , Conor Delaney , Courtney Keiser , Luis A. Jauregui , Paul M. Shand , C. C. Chancey , Yanan Wang , Jiming Bao , Yong P. Chen

We introduce a minimum tight-binding model with only three parameters extracted from graphene and untwisted bilayer graphene. This model reproduces quantitatively the electronic structure of not only these two systems and bulk graphite near…

Mesoscale and Nanoscale Physics · Physics 2018-09-12 Xianqing Lin , David Tománek

We develop a low-energy continuum model for phonons in twisted moir\'e bilayers, based on a configuration-space approach. In this approach, interatomic force constants are obtained from density functional theory (DFT) calculations of…

Mesoscale and Nanoscale Physics · Physics 2023-05-12 Jonathan Z. Lu , Ziyan Zhu , Mattia Angeli , Daniel T. Larson , Efthimios Kaxiras

In the half-filled zero-energy Landau level of bilayer graphene, competing phases with spontaneously broken symmetries and an intriguing quantum critical behavior have been predicted. Here we investigate signatures of these broken-symmetry…

Mesoscale and Nanoscale Physics · Physics 2017-07-19 Falko Pientka , Jonah Waissman , Philip Kim , Bertrand I. Halperin

The electronic properties of twisted bilayer graphene (TBG) can be dramatically different from those of a single graphene layer, in particular when the two layers are rotated relative to each other by a small angle. TBG has recently…

Moir\'{e} systems such as magic-angle twisted bilayer graphene have attracted significant attention due to their ability to host correlated phenomena including superconductivity and strongly correlated insulating states. By defining the…

Strongly Correlated Electrons · Physics 2025-09-08 Liangtao Peng , Giovanni Vignale , Shaffique Adam

The flat electronic bands in magic-angle twisted bilayer graphene (MATBG) host a variety of correlated insulating ground states, many of which are predicted to support charged excitations with topologically non-trivial spin and/or valley…

In this paper, we present a mode space method for atomistic non-equilibrium Green's function simulations of armchair graphene nanoribbon FETs that includes electron-phonon scattering. With reference to both conventional and tunnel FET…

Mesoscale and Nanoscale Physics · Physics 2013-04-12 Roberto Grassi , Antonio Gnudi , Ilaria Imperiale , Elena Gnani , Susanna Reggiani , Giorgio Baccarani

At low-energy, the band structure of graphene can be approximated by two degenerate valleys $(K,K^{\prime})$ about which the electronic spectra of the valence and conduction bands have linear dispersion relations. An electronic state in…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 R. Cote , J. -F. Jobidon , H. A. Fertig

We study the zero-temperature many-body properties of twisted bilayer graphene with a twist angle equal to the so-called `first magic angle'. The system low-energy single-electron spectrum consists of four (eight, if spin label is…

Strongly Correlated Electrons · Physics 2019-07-30 A. O. Sboychakov , A. V. Rozhkov , A. L. Rakhmanov , Franco Nori

The experimentally observed correlated insulating states and quantum anomalous Hall (QAH) effect in twisted bilayer graphene (TBG) have drawn significant attention. However, up to date, the specific mechanisms of these intriguing phenomena…

Strongly Correlated Electrons · Physics 2021-01-27 Jianpeng Liu , Xi Dai

Twisted bilayer graphene with a twist angle of around 1.1{\deg} features a pair of isolated flat electronic bands and forms a strongly correlated electronic platform. Here, we use scanning tunneling microscopy to probe local properties of…

In magic angle twisted bilayer graphene, electron-electron interactions play a central role resulting in correlated insulating states at certain integer fillings. Identifying the nature of these insulators is a central question and…

Strongly Correlated Electrons · Physics 2020-08-19 Nick Bultinck , Eslam Khalaf , Shang Liu , Shubhayu Chatterjee , Ashvin Vishwanath , Michael P. Zaletel