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Related papers: Excitonic effects in twisted bilayer graphene

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We present a comprehensive first-principles study of twisted bilayer graphene (tBLG) for a wide range of twist angles, with a focus on structural and electronic properties. By employing density functional theory (DFT) with an optimized…

Mesoscale and Nanoscale Physics · Physics 2026-05-13 Albert Zhu , Daniel Bennett , Daniel T. Larson , Mohammed M. Al Ezzi , Efstratios Manousakis , Efthimios Kaxiras

We report on the energy spectrum of electrons in twisted bilayer graphene (tBLG) obtained by the band-unfolding method in the tight-binding model. We find the band-gap opening at particular points in the reciprocal space, that elucidates…

Materials Science · Physics 2017-03-08 Hirofumi Nishi , Yu-ichiro Matsushita , Atsushi Oshiyama

We report a theoretical study of the many-body effects of electron-electron interaction on the ground-state and spectral properties of double-layer graphene. Using a projector-based renormalization method we show that if a finite voltage…

Strongly Correlated Electrons · Physics 2015-06-04 Van-Nham Phan , Holger Fehske

The occurrence of superconducting and insulating phases is well-established in twisted graphene bilayers, and they have also been reported in other arrangements of graphene layers. We investigate three such arrangements: untwisted AB…

Strongly Correlated Electrons · Physics 2021-08-11 Pierre A. Pantaleon , Tommaso Cea , Rory Brown , Niels R. Walet , Francisco Guinea

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

The effective theory for bilayer graphene (BLG), subject to parallel/in-plane magnetic fields, is derived. With a sizable magnetic field the trigonal warping becomes irrelevant, and one ends up with two Dirac points in the vicinity of each…

Mesoscale and Nanoscale Physics · Physics 2014-01-08 Bitan Roy , Kun Yang

Twisted bilayer graphene (tBLG) including interlayer interaction and rotational disorder shows anomalous electron transport as a function of twist-angles (tAs). In this work, we address the electronic properties and electron transport of…

Mesoscale and Nanoscale Physics · Physics 2023-06-13 Farzaneh Shayeganfar , Ali Ramazani , Nicholas X Fang

In strongly interacting systems with multiple energy bands, the interplay between electrons with different effective masses and the enlarged Hilbert space drives intricate correlated phenomena that do not occur in single-band systems.…

The Hamiltonian of the magic-angle twisted symmetric trilayer graphene (TSTG) can be decomposed into a TBG-like flat band Hamiltonian and a high-velocity Dirac fermion Hamiltonian. We use Hartree-Fock mean field approach to study the…

Mesoscale and Nanoscale Physics · Physics 2021-10-19 Fang Xie , Nicolas Regnault , Dumitru Călugăru , B. Andrei Bernevig , Biao Lian

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

Twisted bilayer graphene (TwBLG) is one of the simplest van der Waals heterostructures, yet it yields a complex electronic system with intricate interplay between moir\'{e} physics and interlayer hybridization effects. We report on…

Mesoscale and Nanoscale Physics · Physics 2016-09-13 Y. Cao , J. Y. Luo , V. Fatemi , S. Fang , J. D. Sanchez-Yamagishi , K. Watanabe , T. Taniguchi , E. Kaxiras , P. Jarillo-Herrero

We explore the rotational degree of freedom between graphene layers via the simple prototype of the graphene twist bilayer, i.e., two layers rotated by some angle $\theta$. It is shown that, due to the weak interaction between graphene…

Materials Science · Physics 2015-03-13 S. Shallcross , S. Sharma , E. Kandelaki , O. A. Pankratov

We report the observation of anomalously strong 2D band in twisted bilayer graphene (tBLG) with large rotation angles under 638-nm and 532-nm visible laser excitation. The 2D band of tBLG can reach four times as opposed to two times as…

The dominance of Coulomb interactions over kinetic energy of electrons in narrow, non-trivial moir\'{e} bands of magic-angle twisted bilayer graphene (TBG) gives rise to a variety of correlated phases such as correlated insulators,…

The emergence of flat bands in twisted bilayer graphene at the magic angle can be understood in terms of a vanishing Fermi velocity of the Dirac cone. This is associated with van Hove singularities approaching the Fermi energy and becoming…

Strongly Correlated Electrons · Physics 2023-06-05 A. S. Shankar , D. O. Oriekhov , Andrew K. Mitchell , L. Fritz

Spatially separated electron systems remain strongly coupled by electron-electron interactions even when they cannot exchange particles, provided that the layer separation d is comparable to a characteristic distance l between charge…

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

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

Magnetotransport of conventional semiconductor based double layer systems with barrier suppressed interlayer tunneling has been a rewarding subject due to the emergence of an interlayer coherent state that behaves as an excitonic…

Mesoscale and Nanoscale Physics · Physics 2025-01-06 Dohun Kim , Seyoung Jin , Takashi Taniguchi , Kenji Watanabe , Jurgen H. Smet , Gil Young Cho , Youngwook Kim

Twisted bilayer graphene (tBLG) has recently emerged as a platform for hosting correlated phenomena, owing to the exceptionally flat band dispersion that results near interlayer twist angle $\theta\approx1.1^\circ$. At low temperature a…

Strongly Correlated Electrons · Physics 2019-10-03 H. Polshyn , M. Yankowitz , S. Chen , Y. Zhang , K. Watanabe , T. Taniguchi , C. R. Dean , A. F. Young