English
Related papers

Related papers: $\textit{Ab initio}$ four-band Wannier tight-bindi…

200 papers

The emergence of alternating twist multilayer graphene (ATMG) as a generalization of twisted bilayer graphene (TBG) raises the question - in what important ways do these systems differ? Here, we utilize ab-initio relaxation and…

Strongly Correlated Electrons · Physics 2021-11-24 Patrick J. Ledwith , Eslam Khalaf , Ziyan Zhu , Stephen Carr , Efthimios Kaxiras , Ashvin Vishwanath

We generalize the scalable tight-binding model for graphene, which allows for efficient quantum transport simulations in the Dirac regime, to account for elastic strain. We show that the original scalable model with scaling factor $s$ is…

Mesoscale and Nanoscale Physics · Physics 2026-05-28 Ming-Hao Liu , Christophe De Beule , Alina Mreńca-Kolasińska , Hsin-You Wu , Aitor Garcia-Ruiz , Denis Kochan , Klaus Richter

While regular flat bands are good for enhancing the density of states and hence the gap, they are detrimental to the superfluid weight. We show that the predicted nontrivial topology of the two lowest flat bands of twisted bilayer graphene…

Superconductivity · Physics 2020-04-29 Fang Xie , Zhida Song , Biao Lian , B. Andrei Bernevig

Twisted bilayer graphene displays many fascinating properties that can be tuned by varying the relative angle (also called twist angle) between its monolayers. As a remarkable feature, both the electronic flat bands and the corresponding…

Materials Science · Physics 2022-05-06 V. Hung Nguyen , Trinh X. Hoang , J. -C. Charlier

Motivated by the study of flat bands in models of twisted bilayer graphene (TBG), we give abstract conditions which guarantee the existence of a discrete set of parameters for which periodic Hamiltonians exhibit flat bands. As an…

Analysis of PDEs · Mathematics 2023-09-12 Jeffrey Galkowski , Maciej Zworski

Proximity effects resulting from depositing a graphene layer on a TMD substrate layer change the dynamics of the electronic states in graphene, inducing spin orbit coupling (SOC) and staggered potential effects. An effective Hamiltonian…

Mesoscale and Nanoscale Physics · Physics 2016-12-21 Abdulrhman M. Alsharari , Mahmoud M. Asmar , Sergio E. Ulloa

Twisted bilayer graphene (TBG) features strongly correlated and topological phases due to its flat bands emerging near the magic angle. However, the effects of the non-Hermiticity, arising from the coupling to the environment and…

Mesoscale and Nanoscale Physics · Physics 2025-06-06 Juan Pablo Esparza , Vladimir Juricic

A recent experiment reported a large anomalous Hall effect in Magic Angle Twisted Bilayer Graphene (TBG) aligned with a hexagonal boron nitride(h-BN) substrate at $\frac{3}{4}$ filling of the conduction band. In this paper we study this…

Strongly Correlated Electrons · Physics 2019-12-04 Ya-Hui Zhang , Dan Mao , T. Senthil

Evidence of flat-band magnetism and half-metallicity in compressed twisted bilayer graphene is provided with first-principles calculations. We show that dynamic band-structure engineering in twisted bilayer graphene is possible by…

Materials Science · Physics 2019-06-05 Alejandro Lopez-Bezanilla

Nanoscale twisted bilayer graphene (TBG) is quite instable and will change its structure to Bernal (or AB-stacking) bilayer with a much lower energy. Therefore, the lack of nanoscale TBG makes its electronic properties not accessible in…

Mesoscale and Nanoscale Physics · Physics 2017-09-27 Wen-Xiao Wang , Hua Jiang , Yu Zhang , Si-Yu Li , Haiwen Liu , Xinqi Li , Xiaosong Wu , Lin He

We study the electronic structures and topological properties of $(M+N)$-layer twisted graphene systems. We consider the generic situation that $N$-layer graphene is placed on top of the other $M$-layer graphene, and is twisted with respect…

Mesoscale and Nanoscale Physics · Physics 2019-08-14 Jianpeng Liu , Zhen Ma , Jinhua Gao , Xi Dai

Twisted double bilayer graphene has recently emerged as an interesting moir\'e material that exhibits strong correlation phenomena that are tunable by an applied electric field. Here we study the atomic and electronic properties of three…

Accurate modeling of the pi-bands of armchair graphene nanoribbons (AGNRs) requires correctly reproducing asymmetries in the bulk graphene bands as well as providing a realistic model for hydrogen passivation of the edge atoms. The commonly…

Mesoscale and Nanoscale Physics · Physics 2011-08-22 Timothy B. Boykin , Mathieu Luisier , Gerhard Klimeck , Xueping Jiang , Neerav Kharche , Yu Zhou , Saroj K. Nayak

We study a 2D continuum model of electronic transport in twisted bilayer graphene (TBG) at commensurate angles. We use two honeycomb potentials with the symmetries of graphene, either sharing a common origin (AA stacking) or shifted by a…

Mathematical Physics · Physics 2026-05-19 Tal Malinovitch

We develop a model to describe the mixed valence regime in magic-angle twisted bilayer graphene (MATBG) using the recently developed heavy-fermion framework. By employing the large-$N$ slave-boson approach, we derive the self-consistent…

Superconductivity · Physics 2024-07-16 Yantao Li , Benjamin M. Fregoso , Maxim Dzero

We use self-consistent Hartree-Fock calculations performed in the full $\pi$-band Hilbert space to assess the nature of the recently discovered correlated insulator states in magic-angle twisted bilayer graphene (TBG). We find that gaps…

Strongly Correlated Electrons · Physics 2020-03-11 Ming Xie , Allan H. MacDonald

When two graphene sheets are twisted relative to each other by a small angle, enhanced correlations lead to superconductivity whose origin remains under debate. Here, we derive some general constraints on superconductivity in twisted…

Superconductivity · Physics 2023-07-25 Eslam Khalaf , Patrick Ledwith , Ashvin Vishwanath

We introduce a complete physical model for the single-particle electronic structure of twisted bilayer graphene (tBLG), which incorporates the crucial role of lattice relaxation. Our model, based on $k \cdot p$ perturbation theory, combines…

Mesoscale and Nanoscale Physics · Physics 2019-08-14 Stephen Carr , Shiang Fang , Ziyan Zhu , Efthimios Kaxiras

When two monolayers of graphene are stacked with a small relative twist angle, the resulting band structure exhibits a remarkably flat pair of bands at a sequence of 'magic angles' where correlation effects can induce a host of exotic…

Strongly Correlated Electrons · Physics 2019-08-14 Eslam Khalaf , Alex J. Kruchkov , Grigory Tarnopolsky , Ashvin Vishwanath

A theoretical model is presented to compute the electronic band structures and optical absorption spectra for twisted incommensurate few-layers graphene (tLFG) systems of arbitrary architecture. This is accomplished using an integrated…

Mesoscale and Nanoscale Physics · Physics 2015-04-07 D. Ghader , A. Khater , D. Szczȩśniak