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Related papers: Trions in Twisted Bilayer Graphene

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We derive the exact insulator ground states of the projected Hamiltonian of magic-angle twisted bilayer graphene (TBG) flat bands with Coulomb interactions in various limits, and study the perturbations away from these limits. We define the…

Strongly Correlated Electrons · Physics 2022-04-29 Biao Lian , Zhi-Da Song , Nicolas Regnault , Dmitri K. Efetov , Ali Yazdani , B. Andrei Bernevig

Using exact diagonalization, we study the projected Hamiltonian with Coulomb interaction in the 8 flat bands of first magic angle twisted bilayer graphene. Employing the U(4) (U(4)$\times$U(4)) symmetries in the nonchiral (chiral) flat band…

Strongly Correlated Electrons · Physics 2022-04-26 Fang Xie , Aditya Cowsik , Zhi-Da Song , Biao Lian , B. Andrei Bernevig , Nicolas Regnault

We study ferromagnetism and its stability in twisted bilayer graphene. We work with a Hubbard-like interaction that corresponds to the screened Coulomb interaction in a well-defined limit where the Thomas-Fermi screening length…

Mesoscale and Nanoscale Physics · Physics 2021-01-04 Yahya Alavirad , Jay D. Sau

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,…

Magic-angle twisted bilayer graphene (TBG), with rotational misalignment close to 1.1$^\circ$, features isolated flat electronic bands that host a rich phase diagram of correlated insulating, superconducting, ferromagnetic, and topological…

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…

Although much progress has been made on the physics of magic angle twisted bilayer graphene at integer fillings, little attention has been given to fractional fillings. Here we show that the three-peak structure of Wannier orbitals,…

Mesoscale and Nanoscale Physics · Physics 2021-05-31 Kevin Zhang , Yang Zhang , Liang Fu , Eun-Ah Kim

We introduce twisted trilayer graphene (tTLG) with two independent twist angles as an ideal system for the precise tuning of the electronic interlayer coupling to maximize the effect of correlated behaviors. As established by experiment and…

Mesoscale and Nanoscale Physics · Physics 2020-10-12 Ziyan Zhu , Stephen Carr , Daniel Massatt , Mitchell Luskin , Efthimios Kaxiras

We find exact analytic expressions for the energies and wavefunctions of the charged and neutral excitations above the exact ground states (at rational filling per unit cell) of projected Coulomb Hamiltonians in twisted bilayer graphene.…

Strongly Correlated Electrons · Physics 2022-04-29 B. Andrei Bernevig , Biao Lian , Aditya Cowsik , Fang Xie , Nicolas Regnault , Zhi-Da Song

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

The nature of charge carriers in twisted bilayer graphene (TBG) near $\nu = -2$, where superconductivity emerges, remains mysterious. While various symmetry-broken ground states have been proposed, experimental evidence of significant…

Strongly Correlated Electrons · Physics 2025-05-14 Patrick J. Ledwith , Ashvin Vishwanath , Eslam Khalaf

We consider the most energetically favorable symmetry-allowed spin-singlet and spin-triplet superconducting pairing symmetries in twisted bilayer graphene at the magic angle, whose normal state physics is described by a six-band effective…

Superconductivity · Physics 2023-07-27 Emile Pangburn , Miguel Alvarado , Oladunjoye A. Awoga , Catherine Pépin , Cristina Bena

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 the vicinity of the magic angle in twisted bilayer graphene (TBG), the two low-energy van Hove singularities (VHSs) become exceedingly narrow1-10 and many exotic correlated states, such as superconductivity, ferromagnetism, and…

Strongly Correlated Electrons · Physics 2020-02-25 Yu Zhang , Zhe Hou , Ya-Xin Zhao , Zi-Han Guo , Yi-Wen Liu , Si-Yu Li , Ya-Ning Ren , Qing-Feng Sun , Lin He

When one of the graphene layers of Magic Angle Twisted Bilayer Graphene is nearly aligned with its hexagonal boron nitride substrate (a configuration dubbed TBG/hBN), the active electronic bands are nearly flat, and have a Chern number…

Strongly Correlated Electrons · Physics 2019-12-25 Cécile Repellin , T. Senthil

The effect of an hexagonal boron nitride (hBN) layer close aligned with twisted bilayer graphene (TBG) is studied. At sufficiently low angles between twisted bilayer graphene and hBN, $\theta_{hBN} \lesssim 2^\circ$, the graphene electronic…

Strongly Correlated Electrons · Physics 2020-10-28 Tommaso Cea , Pierre A. Pantaleon , Francisco Guinea

We study the collective excitation modes of the Chern insulator states in magic-angle twisted bilayer graphene aligned with hexagonal boron nitride (TBG/BN) at odd integer fillings ($\nu$) of the flat bands. For the $1 \times 1$…

Mesoscale and Nanoscale Physics · Physics 2023-06-07 Xianqing Lin , Quan Zhou , Cheng Li , Jun Ni

Twisted bilayer graphene exhibits isolated, relatively flat electronic bands near charge neutrality when the interlayer rotation is tuned to specific magic angles. These small misalignments, typically below 1.1{\deg}, result in long-period…

Mesoscale and Nanoscale Physics · Physics 2026-03-26 Antonio Palamara , Michele Pisarra , Antonello Sindona

Twisted bilayer graphene (TBG) hosts a rich landscape of electronic phases arising from the interplay between strong electron-electron interactions and nontrivial band topology. While the flat bands near zero energy are central to many…

Mesoscale and Nanoscale Physics · Physics 2026-02-16 Leonardo A. Navarro-Labastida , Pierre A. Pantaleon , Francisco Guinea , Gerardo G. Naumis

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
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