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Related papers: Topological Phases in Graphitic Cones

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Graphene ripples possess peculiar essential properties owing to the strong chemical bonds, as an investigation using first principle calculations clearly revealed. Various charge distributions, bond lengths, energy bands, and densities of…

Materials Science · Physics 2015-01-08 Shih-Yang Lin , Shen-Lin Chang , Feng-Lin Shyu , Jian-Ming Lu , Ming-Fa Lin

In this note, we calculate the electronic properties of a realistic atomistic model of amorphous graphene. The model contains odd membered rings, particularly five and seven membered rings and no coordination defects. We show that…

Strongly Correlated Electrons · Physics 2009-12-04 V. Kapko , D. A. Drabold , M. F. Thorpe

We show that the critical charge for the Dirac excitations in gapless graphene depends on the spatial topology of the sample. In particular, for graphene cones, the effective value of the critical charge can tend towards zero for a suitable…

Mesoscale and Nanoscale Physics · Physics 2011-07-26 Baishali Chakraborty , Kumar S. Gupta , Siddhartha Sen

A theory for nontrivial topology of band structure in metallic helimagnets is developed. Two theorems on electron dispersion in helimagnets are proved. They reveal a Kramers-like degeneracy in helical magnetic field. The generalized Bloch…

Other Condensed Matter · Physics 2024-12-24 Yu. B. Kudasov

We extend the definition of hopfions to include a class of spin-$h$ fields and use this to introduce the electromagnetic and gravitational hopfions of different algebraic types. The fields are constructed through the Penrose contour…

General Relativity and Quantum Cosmology · Physics 2015-05-20 Amy Thompson , Alexander Wickes , Joe Swearngin , Dirk Bouwmeester

Soft magnetic dots in the form of thin rings have unique topological properties. They can be in a vortex state with no vortex core. Here, we study the magnon modes of such systems both analytically and numerically. In an external magnetic…

Mesoscale and Nanoscale Physics · Physics 2023-12-11 Vera Uzunova , Lukas Körber , Agapi Kavvadia , Gwendolyn Quasebarth , Helmut Schultheiss , Attila Kákay , Boris Ivanov

This paper focuses on the structural, electronic, and vibrational features of amorphous graphite [R. Thapa $\textit{et. al.}$, Phys. Rev. Lett. 128, 236402 (2022)]. The structure order in amorphous graphite is discussed and compared with…

Materials Science · Physics 2023-05-09 C. Ugwumadu , K. Nepal , R. Thapa , D. A. Drabold

Hydrogen adatoms are one of the most the promising proposals for the functionalization of graphene. Hydrogen induces narrow resonances near the Dirac energy, which lead to the formation of magnetic moments. Furthermore, they also create…

Mesoscale and Nanoscale Physics · Physics 2018-04-24 Luis A. González-Árraga , J. L. Lado , F. Guinea

This paper is devoted to topological phenomena in normal metals with rather complicated Fermi surface. The results of the article are based on the deep topological theorems concerning the geometry of non-compact plane sections of level…

Condensed Matter · Physics 2009-10-30 S. P. Novikov , A. Ya. Maltsev

The $\pi$-electronic structure of graphene in the presence of a modulated electric potential is investigated by the tight-binding model. The low-energy electronic properties are strongly affected by the period and field strength. Such a…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 J. H. Ho , Y. H. Chiu , S. J. Tsai , M. F. Lin

Topological phases are characterised by a topological invariant that remains unchanged by deformations in the Hamiltonian. Materials exhibiting topological phases include topological insulators, superconductors exhibiting strong spin-orbit…

Mesoscale and Nanoscale Physics · Physics 2019-07-08 Dimitrie Culcer , Attila Geresdi

We study the electronic structure of graphene in the presence of either sevenfolds or eightfolds by using a gauge field-theory model. The graphene sheet with topological defects is considered as a negative cone surface with infinite…

Materials Science · Physics 2009-11-13 D. V. Kolesnikov , V. A. Osipov

In neutral graphene dots the Fermi level coincides with the Dirac points. We have investigated in the presence of a magnetic field several unusual properties of single electron states near the Fermi level of such a rectangular-shaped…

Mesoscale and Nanoscale Physics · Physics 2010-02-24 S. C. Kim , P. S. Park , S. -R. Eric Yang

The growing skill in the synthesis processes of new materials has intensified the interest in exploring the properties of systems modeled by more complex lattices. Two-dimensional super-honeycomb lattices, have been investigated in metallic…

Mesoscale and Nanoscale Physics · Physics 2023-02-03 A. B. Felix de Souza , L. Spreafico , D. Faria , A. Latgé

We use angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT) calculations to study the electronic structure of CaFe$_2$As$_2$ in previously unexplored collapsed tetragonal (CT) phase. This unusual phase of…

Knowledge of the topology of the electronic ground state of materials has led to deep insights to novel phenomena such as the integer quantum Hall effect and fermion-number fractionalization, as well as other properties of matter. Joining…

Mesoscale and Nanoscale Physics · Physics 2017-08-18 Ting Cao , Fangzhou Zhao , Steven G. Louie

Magnetic topological semimetals, a novel state of quantum matter with nontrivial band topology, have emerged as a new frontier in physics and materials science. An external stimulus like temperature or magnetic field could be expected to…

The electronic shell structure of triangular, hexagonal and round graphene quantum dots (flakes) near the Fermi level has been studied using a tight-binding method. The results show that close to the Fermi level the shell structure of a…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 H. P. Heiskanen , M. Manninen , J. Akola

We propose a way to generate a one-dimensional topological superconductor from a monolayer of a transition metal dichalcogenide coupled to a Bernal-stacked bilayer of graphene under a displacement field. With proper gating, this structure…

Mesoscale and Nanoscale Physics · Physics 2025-10-03 Daniel Skliannyi , Yuval Oreg , Ady Stern

Epitaxial graphene films have been formed on the C-face of semi-insulating 4H-SiC substrates by a high temperature sublimation process. Nano-scale square antidot arrays have been fabricated on these graphene films. At low temperatures,…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 T. Shen , Y. Q. Wu , M. A. Capano , L. R. Rokhinson , L. W. Engel , P. D. Ye