Flat bands without twists: periodic holey graphene DOI Creative Commons
Abdiel de Jesús Espinosa-Champo, Gerardo G. Naumis

arXiv (Cornell University), Journal Year: 2023, Volume and Issue: unknown

Published: Jan. 1, 2023

\textit{Holey Graphene} (HG) is a widely used graphene material for the synthesis of high-purity and highly crystalline materials. In this work, we explore electronic properties periodic distribution lattice holes, demonstrating emergence flat bands with compact localized states. It shown that holes break bipartite sublattice inversion symmetries, inducing gaps nonzero Berry curvature. Moreover, folding Dirac cones from hexagonal Brillouin zone (BZ) to holey superlattice rectangular BZ HG sizes proportional an integer $n$ times graphene's parameter leads periodicity in gap formation such $n \equiv 0$ (mod $3$). Meanwhile, it if \pm 1$ $3$), emerges where points are folded along $\Gamma-X$ path. The low-energy hamiltonian three central also obtained, revealing system behaves as effective $\alpha-\mathcal{T}_{3}$ material. Therefore, simple protocol presented here allows obtaining at will. Such known increase electron-electron correlated effects. This work provides alternative system, much easier build than twisted systems, obtain quantum phases.

Language: Английский

Approximate solutions for electronic states with non-standard Landau levels in graphene under uniaxial strain modulation DOI
Juan D. García-Muñoz, Julio César Pérez-Pedraza, Alfredo Raya

et al.

Physics Letters A, Journal Year: 2025, Volume and Issue: 536, P. 130305 - 130305

Published: Jan. 29, 2025

Language: Английский

Citations

1
Mechanical, electronic, optical, piezoelectric and ferroic properties of strained graphene and other strained monolayers and multilayers: an update DOI Creative Commons
Gerardo G. Naumis, Saúl A. Herrera, Shiva Prasad Poudel

et al.

Reports on Progress in Physics, Journal Year: 2023, Volume and Issue: 87(1), P. 016502 - 016502

Published: Oct. 25, 2023

Abstract This is an update of a previous review (Naumis et al 2017 Rep. Prog. Phys. 80 096501). Experimental and theoretical advances for straining graphene other metallic, insulating, ferroelectric, ferroelastic, ferromagnetic multiferroic 2D materials were considered. We surveyed (i) methods to induce valley sublattice polarisation ( P ) in graphene, (ii) time-dependent strain its impact on graphene’s electronic properties, (iii) the role local global superconductivity highly correlated and/or topological phases (iv) inducing hexagonal boron nitride monolayers via strain, (v) modifying optoelectronic properties transition metal dichalcogenide through (vi) ferroic with intrinsic elastic σ ), electric magnetic M under as well incipient multiferroics (vii) moiré bilayers exhibiting flat bands exotic quantum phase diagrams, bilayer or few-layer systems orders tunable by rotations shear strain. The features experimental realisations two-dimensional Quantum Spin Hall effect germanene, elemental ferroelectric bismuth, NiI 2 . document was structured discussion effects taking place first, followed discussions concerning few-layers, it represents up-to-date overview exciting newest developments fast-paced field materials.

Language: Английский

Citations

16
Strained Graphene as Pristine Graphene with a Deformed Momentum Operator DOI Creative Commons
David Valenzuela, Alfredo Raya, Juan D. García-Muñoz

et al.

Condensed Matter, Journal Year: 2025, Volume and Issue: 10(1), P. 10 - 10

Published: Feb. 7, 2025

We explore the equivalence between low-energy dynamics of strained graphene and a quantum mechanical framework for 2D Dirac equation in flat space with deformed momentum operator. By considering some common forms anisotropic Fermi velocity tensor emerging from elasticity theory, we associate such deformation first bound states charge carriers background uniform magnetic field this quantify impact strain energy spectrum. Then, use quadrature algebra formula as mathematical tool to analyze attached operator identify physical consequences terms modifications due applied strain.

Language: Английский

Citations

0
Protected fermionic zero modes in periodic gauge fields DOI
Võ Tiến Phong, E. J. Melé

Physical review. B./Physical review. B, Journal Year: 2025, Volume and Issue: 111(12)

Published: March 11, 2025

Language: Английский

Citations

0
Quantum percolation on Lieb Lattices DOI
W. S. Oliveira, J.P. de Lima, Raimundo R. dos Santos

et al.

Physical review. E, Journal Year: 2025, Volume and Issue: 111(3)

Published: March 13, 2025

We theoretically investigate the quantum percolation problem on Lieb lattices in two and three dimensions. study statistics of energy levels through random matrix theory determine level spacing distributions, which, with aid finite-size scaling theory, allows us to obtain accurate estimates for site- bond-percolation thresholds critical exponents. Our numerical investigation supports a localized-delocalized transition at finite threshold, which decreases as average coordination number increases. The precise determination localization length exponent enables claim that problems belong same universality class, ν decreasing lattice dimensionality d, similarly classical problem. In addition, we verify that, dimensions, belongs class Anderson impurity model.

Language: Английский

Citations

0
Dislocation patterning as a mechanism for flat band formation DOI
Aziz Fall, Kaushik Dayal

Physical review. B./Physical review. B, Journal Year: 2025, Volume and Issue: 111(15)

Published: April 10, 2025

Language: Английский

Citations

0
Approximate solutions for uniaxially strained graphene DOI Open Access
Juan D. García-Muñoz, Alfredo Raya, Julio César Pérez-Pedraza

et al.

Journal of Physics Conference Series, Journal Year: 2025, Volume and Issue: 2986(1), P. 012003 - 012003

Published: March 1, 2025

Abstract Approximate solutions for a electron in uniaxially strained graphene have been determined. A first-order Taylor expansion the Fermi velocities and pseudo-vector potential, effective Hamiltonian describing graphene, allows us to solve corresponding differential equation of eigenvalue problem. finite number bound states found its spectrum is compared with zero-order approximation derived [1]. It turns out that generated less energy levels than approximation, revealing suppression mechanism deletes some levels.

Language: Английский

Citations

0
Flat bands and electronic localization in twisted bilayer graphene nanoribbons DOI
Elías Andrade, Pierre A. Pantaleón, F. Guinea

et al.

Physical review. B./Physical review. B, Journal Year: 2023, Volume and Issue: 108(23)

Published: Dec. 13, 2023

In an infinite twisted bilayer graphene lattice, flat bands emerge, representing electrons localized at the AA stacking regions. This study investigates behavior of these when dealing with incomplete moir\'e supercells in nanoribbons. The findings reveal a transition from dispersive to near charge neutrality as supercell completeness varies. Moreover, it is observed that microscopic edges can influence energy states regions borders.

Language: Английский

Citations

8
Self-duality properties, localization centers, and magnetic energy of the electronic wave functions at small magic angles in twisted bilayer graphene DOI
Leonardo A. Navarro-Labastida, Gerardo G. Naumis

Physical review. B./Physical review. B, Journal Year: 2024, Volume and Issue: 109(3)

Published: Jan. 3, 2024

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. The connection between and quantum Hall effect remains a topic ongoing research. In TBG chiral model, electronic wave function properties depend on single parameter ($\ensuremath{\alpha}$), inversely proportional relative twist angle two layers ($\ensuremath{\theta}$), which includes interlayer interaction strength. previous studies, as approached small values, strong confinement convergence coherent Landau states were observed. However, origin these phenomena remained elusive. this paper, we explore band modes, revealing exhibit self-duality; they are in reciprocal space minimal dispersion, with standard deviation ${\ensuremath{\sigma}}_{k}=\sqrt{3\ensuremath{\alpha}/2\ensuremath{\pi}}$ $\ensuremath{\theta}\ensuremath{\rightarrow}0$. Subsequently, by symmetrizing functions considering squared Hamiltonian, observed $\ensuremath{\theta}\ensuremath{\rightarrow}0$ limit explained. This arises from combination symmetrized norm moir\'e potential quantized orbital motion electrons, effectively creating well. ground state well, located non-high-symmetry spots, corresponds level. Furthermore, demonstrate problem physically analogous an electron attached non-Abelian $\text{SU}(2)$ gauge field underlying ${C}_{3}$ symmetry. regions confinement, system can be considered Abelian, aligning picture simple harmonic oscillator. allows us define magnetic energy important role parity gap closing nonmagic revealed. Finally, investigate transition original nature Abelian artificially changing pseudomagnetic vector components U(1) field, alters sequence angles. An experimental proposal made measure such effects.

Language: Английский

Citations

2
Absence of edge states at armchair edges in inhomogeneously strained graphene under a pseudomagnetic field DOI
Jingyun Fang, Yu-Chen Zhuang, Qing‐Feng Sun

et al.

Physical review. B./Physical review. B, Journal Year: 2024, Volume and Issue: 109(4)

Published: Jan. 23, 2024

Nonuniform strain in graphene can induce a pseudo-magnetic field (PMF) preserving time-reversal symmetry, generating pseudo-Landau levels under zero real magnetic (MF). The different natures between PMF and MF lead to the counterpropagating valley-polarized edge states unidirectionally chiral MF. In this work, we find, due valley mixing on armchair edges, quantum Hall only exist at zigzag edges but not uniaxial strained graphene, very from case that all pristine We theoretically demonstrate it through wave function distributions, multi-terminal transport measurements electron local occupations, respectively. interface state p-n junction is further proposed electrons conductive boundaries, which could be used as single pole double throw switch.

Language: Английский

Citations

2