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Related papers: General continuum model for twisted bilayer graphe…

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We show that the entire continuous model of twisted bilayer graphene (TBG) (and not just the two active bands) with particle-hole symmetry is anomalous and hence incompatible with a lattice model. Previous works, e.g., [Phys. Rev. Lett.…

Mesoscale and Nanoscale Physics · Physics 2022-04-29 Zhi-Da Song , Biao Lian , Nicolas Regnault , B. Andrei Bernevig

We introduce a notion of stability for non-autonomous Hamiltonian flows on two-dimensional annular surfaces. This notion of stability is designed to capture the sustained twisting of particle trajectories. The main Theorem is applied to…

Analysis of PDEs · Mathematics 2024-08-30 Theodore D. Drivas , Tarek M. Elgindi , In-Jee Jeong

We study a $R^{2}$ model of gravity with torsion in a closed Friedmann-Robertson-Walker universe. The model is cast in Hamiltonian form subtracting from the original Lagrangian the total time derivative of $f_{K}f_{R}$, where $f_{K}$ is…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Giampiero Esposito

We model the low energy dynamics of graphene in the continuum in terms of a version of Reduced Quantum Electrodynamics restricting fermions to a (2+1)-dimensional brane, whilst photons remain within the (3+1)-dimensional bulk. For charge…

Mesoscale and Nanoscale Physics · Physics 2016-05-25 Saúl Hernández-Ortiz , David Valenzuela , Alfredo Raya , Saúl Sánchez-Madrigal

Twisted bilayer graphene is a chiral system which has been recently shown to present circular dichroism. In this work we show that the origin of this optical activity is the rotation of the Dirac fermions' helicities in the top and bottom…

Materials Science · Physics 2017-09-18 E. Suarez Morell , Leonor Chico , Luis Brey

We revise the tight binding approach to strained or curved graphene in the presence of external probes such as Photoemission or Scanning Tunneling Microscopy experiments. We show that extra terms arise in the continuum limit of the tight…

Mesoscale and Nanoscale Physics · Physics 2015-06-12 Fernando de Juan , Juan L. Mañes , María A. H. Vozmediano

We construct a Wannier basis for twisted bilayer graphene that is projected only from the Bloch functions of the twisted bilayer flat bands. The $C_3$ and $C_{2} \mathcal{T}$ symmetries act locally on the Wannier functions while the Wannier…

Mesoscale and Nanoscale Physics · Physics 2022-10-25 Jiawei Zang , Jie Wang , Antoine Georges , Jennifer Cano , Andrew J. Millis

This work deals with several aspects of the extension to Abelian Higgs models of the deformation method originally developed for scalar field models. We present several examples allowing to transform self-dual solutions of different…

High Energy Physics - Theory · Physics 2012-04-11 C. dos Santos , D. Rubiera-Garcia

We present a formal derivation of a drift-diffusion model for stationary electron transport in graphene, in presence of sharp potential profiles, such as barriers and steps. Assuming the electric potential to have steep variations within a…

Mathematical Physics · Physics 2020-06-02 Luigi Barletti , Claudia Negulescu

Discontinuities in spatial derivatives appear in a wide range of physical systems, from creased thin sheets to materials with sharp stiffness transitions. Accurately modeling these features is essential for simulation but remains…

Graphics · Computer Science 2025-05-28 Mengfei Liu , Yue Chang , Zhecheng Wang , Peter Yichen Chen , Eitan Grinspun

We prove absolute continuity for an extended class of two-dimensional magnetic Hamiltonians that were initially studied by A. Iwatsuka. In particular, we add an electric field that is translation invariant in the same direction as the…

Mathematical Physics · Physics 2017-01-30 Matej Tusek

We extend to curved backgrounds all flat-space scalar field models that obey purely second-order equations, while maintaining their second-order dependence on both field and metric. This extension simultaneously restores to second order…

General Relativity and Quantum Cosmology · Physics 2009-10-07 C. Deffayet , S. Deser , G. Esposito-Farese

A Drude-Boltzmann theory is used to calculate the transport properties of bilayer graphene. We find that for typical carrier densities accessible in graphene experiments, the dominant scattering mechanism is overscreened Coulomb impurities…

Mesoscale and Nanoscale Physics · Physics 2008-03-22 Shaffique Adam , S. Das Sarma

The electronic properties of graphene under any arbitrary uniaxial strain field are obtained by an exact mapping of the corresponding tight-binding Hamiltonian into an effective one-dimensional modulated chain. For a periodic modulation,…

Mesoscale and Nanoscale Physics · Physics 2015-06-19 Gerardo G. Naumis , Pedro Roman-Taboada

This work theoretically explores how to emulate twisted double bilayer graphene with ultracold atoms in multiorbital optical lattices. In particular, the quadratic band touching of Bernal stacked bilayer graphene is emulated using a square…

Quantum Gases · Physics 2021-12-28 Junhyun Lee , J. H. Pixley

We study the influence of different kinds of gaps in a quasiparticle spectrum on longitudinal and transverse optical conductivities of bilayer graphene. An exact analytical expression for magneto-optical conductivity is derived using a…

Strongly Correlated Electrons · Physics 2012-08-08 E. V. Gorbar , V. P. Gusynin , A. B. Kuzmenko , S. G. Sharapov

The inclusion of a flat metric tensor in gravitation permits the formulation of a gravitational stress-energy tensor and the formal derivation of general relativity from a linear theory in flat spacetime. Building on the works of Kraichnan…

General Relativity and Quantum Cosmology · Physics 2015-06-25 J. Brian Pitts , W. C. Schieve

We present a new first-order approach to strain-engineering of graphene's electronic structure where no continuous displacement field $\mathbf{u}(x,y)$ is required. The approach is valid for negligible curvature. The theory is directly…

Mesoscale and Nanoscale Physics · Physics 2013-10-15 Salvador Barraza-Lopez , Alejandro A. Pacheco Sanjuan , Zhengfei Wang , Mihajlo Vanevic

Using the Wilson formulation of lattice gauge theories, a gauge invariant grid discretization of a one-particle Hamiltonian in the presence of an external electromagnetic field is proposed. This Hamiltonian is compared both with that…

Condensed Matter · Physics 2016-08-31 M. Governale , C. Ungarelli

We introduce a Hamiltonian lattice model for the $(1+1)$-dimensional $\text{SU}(N_c)$ gauge theory coupled to one adjoint Majorana fermion of mass $m$. The discretization of the continuum theory uses staggered Majorana fermions. We analyze…

High Energy Physics - Theory · Physics 2024-05-02 Ross Dempsey , Igor R. Klebanov , Silviu S. Pufu , Benjamin T. Søgaard