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Graphene-based multilayer systems serve as versatile platforms for exploring the interplay between electron correlation and topology, thanks to distinctive low-energy bands marked by significant quantum metric and Berry curvature from…

Strongly Correlated Electrons · Physics 2026-01-30 Niklas Witt , Siheon Ryee , Lennart Klebl , Jennifer Cano , Giorgio Sangiovanni , Tim O. Wehling

We consider Friedel oscillation in the two-dimensional Dirac materials when Fermi level is near the van Hove singularity. Twisted graphene bilayer and the surface state of topological crystalline insulator are the representative materials…

Mesoscale and Nanoscale Physics · Physics 2016-01-25 Chi-Ken Lu

Two monolayers of graphene twisted by a small `magic' angle exhibit nearly flat bands leading to correlated electronic states and superconductivity, whose precise nature including possible broken symmetries, remain under debate. Here we…

Strongly Correlated Electrons · Physics 2019-12-13 Jong Yeon Lee , Eslam Khalaf , Shang Liu , Xiaomeng Liu , Zeyu Hao , Philip Kim , Ashvin Vishwanath

We show that the twisted graphene bilayer can reveal unusual topological properties at low energies, as a consequence of a Dirac-point splitting. These features rely on a symmetry analysis of the electron hopping between the two layers of…

Mesoscale and Nanoscale Physics · Physics 2011-07-21 R. de Gail , M. O. Goerbig , F. Guinea , G. Montambaux , A. H. Castro Neto

Electrons in quantum materials exhibiting coexistence of dispersionless (flat) bands piercing dispersive (steep) bands can give rise to strongly correlated phenomena, and are associated with unconventional superconductivity. It is known…

Strongly Correlated Electrons · Physics 2020-06-01 Stephen Carr , Chenyuan Li , Ziyan Zhu , Efthimios Kaxiras , Subir Sachdev , Alex Kruchkov

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

When two layers of two-dimensional materials are assembled with a relative twist, moir\'e patterns arise, inducing a tremendous wealth of exotic phenomena. In this work, we consider twisting two triangular lattices hosting Dirac quantum…

Strongly Correlated Electrons · Physics 2022-11-09 Zhu-Xi Luo , Urban F. P. Seifert , Leon Balents

The paper presents the author view on spin-rooted properties of graphene supported by numerous experimental and calculation evidences. Dirac fermions of crystalline graphene and local spins of graphene molecules are suggested to meet a…

Materials Science · Physics 2016-12-28 Elena F. Sheka

We study the electronic properties of a twisted trilayer graphene, where two of the layers have Bernal stacking and the third one has a relative rotation with respect to the AB-stacked layers. Near the Dirac point, the AB-twisted trilayer…

Mesoscale and Nanoscale Physics · Physics 2013-04-02 E. Suárez Morell , M. Pacheco , L. Chico , L. Brey

In a system with a Dirac-like linear dispersion there are always states that fulfill the resonance condition for electromagnetic radiation of arbitrary frequency $\Omega$. When a flat band is present two kinds of resonant transitions are…

Mesoscale and Nanoscale Physics · Physics 2022-02-02 M. A. Mojarro , V. G. Ibarra-Sierra , J. C. Sandoval-Santana , R. Carrillo-Bastos , Gerardo G. Naumis

This work investigates the electronic properties of twisted bilayer graphene (TBG) through computational calculations, with the aim of understanding the emergence of flat bands and conditions favorable for superconductivity close to the…

Mesoscale and Nanoscale Physics · Physics 2026-01-21 Rajendra Paudel , Nabin Upadhya Dhakal , Nurapati Pantha

We extensively investigate the electronic and transport properties of a twisted bilayer graphene when subjected to both an external perpendicular electric field and a magnetic field. Using a basic tight-binding model, we show the flat…

Mesoscale and Nanoscale Physics · Physics 2023-11-13 Priyanka Sinha , Ayan Mondal , Simão Meneses João , Bheema Lingam Chittari

The possibility of triggering correlated phenomena by placing a singularity of the density of states near the Fermi energy remains an intriguing avenue towards engineering the properties of quantum materials. Twisted bilayer graphene is a…

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

Transport experiments in twisted bilayer graphene revealed multiple superconducting domes separated by correlated insulating states. These properties are generally associated with strongly correlated states in a flat mini-band of the…

At magic twisted angles, Dirac cones in twisted bilayer graphene (TBG) can evolve into flat bands, serving as a critical playground for the study of strongly correlated physics. When chiral symmetry is introduced, rigorous mathematical…

Strongly Correlated Electrons · Physics 2023-10-11 Fan Cui , Congcong Le , Qiang Zhang , Xianxin Wu , Jiangping Hu , Ching-Kai Chiu

We investigate magic-angle twisted bilayer graphene (MATBG) with proximity-induced Ising and Rashba spin-orbit couplings (SOC) in the top layer, as recently achieved experimentally. Utilizing the Bistritzer-MacDonald model with SOCs, we…

Mesoscale and Nanoscale Physics · Physics 2024-10-10 Yuting Tan , Yang-Zhi Chou , Fengcheng Wu , Sankar Das Sarma

Twisted bilayer graphene (TBG) hosts nearly flat bands with narrow bandwidths of a few meV at certain {\em magic} twist angles. Here we show that in twisted gapped Dirac material bilayers, or massive twisted bilayer graphenes (MTBG),…

Mesoscale and Nanoscale Physics · Physics 2020-03-18 Srivani Javvaji , Jinhua Sun , Jeil Jung

We investigate the effect of spin-orbit coupling on the band structure of graphene-based two-dimensional Dirac fermion gases in the quantum Hall regime. Taking monolayer graphene as our first candidate, we show that a quantum phase…

Mesoscale and Nanoscale Physics · Physics 2013-06-11 Pierre Carmier , Oleksii Shevtsov , Christoph Groth , Xavier Waintal

The spectrum of tight binding electrons on a square lattice with half a magnetic flux quantum per unit cell exhibits two Dirac points at the band center. We show that, in the presence of an additional uniaxial staggered potential, this pair…

Mesoscale and Nanoscale Physics · Physics 2011-01-06 P. Delplace , G. Montambaux