Related papers: Spectral gaps in graphene antidot lattices

Graphene, being one-atom thick, is extremely sensitive to the presence of adsorbed atoms and molecules and, more generally, to defects such as vacancies, holes and/or substitutional dopants. This property, apart from being directly usable…

In order to use graphene for semiconductor applications, such as transistors with high on/off ratios, a band gap must be introduced into this otherwise semimetallic material. A promising method of achieving a band gap is by introducing…

Motivated by the recently observed sublattice asymmetry of substitutional nitrogen impurities in CVD grown graphene, we show, in a mathematically transparent manner, that oscillations in the local density of states driven by the presence of…

We present a tight-binding investigation of strained bilayer graphene within linear elasticity theory, focusing on the different environments experienced by the A and B carbon atoms of the different sublattices. We find that the…

The zero gap electronic bands in the monolayer graphene are shown to be unstable relative to the dynamic symmetry violation due to the electron-phonon interaction.

Spatial gaps correspond to the projection in position space of the gaps of a periodic structure whose envelope varies spatially. They can be easily generated in cold atomic physics using finite-size optical lattice, and provide a new kind…

Using ab-initio methods, we show that the uniform deformation either leaves graphene (semi)metallic or opens up a small gap yet only beyond the mechanical breaking point of the graphene, contrary to claims in the literature based on…

The pi bands of epitaxially grown graphene are studied by using high resolution angle resolved photoemission spectroscopy. Clear deviations from the conical dispersion expected for massless Dirac fermions and an anomalous increase of the…

By using two ab initio numerical methods we study the effects that disorder has on the spectral gaps and on wave localization in two-dimensional photonic band gap materials. We find that there are basically two different responses depending…

We show that patterned defects can be used to disrupt the sub-lattice symmetry of graphene so as to open up a band gap. This way of modifying graphene's electronic structure does not rely on external agencies, the addition of new elements…

We establish an upper bound on the spectral gap for compact quantum graphs which depends only on the diameter and total number of vertices. This bound is asymptotically sharp for pumpkin chains with number of edges tending to infinity.

Among the different strategies used to induce the opening of a band gap in graphene, one common practice is through chemical doping. While a gap may me opened in this way, disorder-induced scattering is an unwanted side-effect that impacts…

We report the exact solution of spectral problem for a graphene sheet framed by two armchair- and two zigzag-shaped boundaries. The solution is found for the $\pi$ electron Hamiltonian and gives, in particular, a closed analytic expression…

Recent experimental findings and theoretical predictions suggest that nitrogen-doped CVD-grown graphene may give rise to electronic band gaps due to impurity distributions which favour segregation on a single sublattice. Here we demonstrate…

The interaction between a graphene layer and a hexagonal Boron Nitride (hBN) substrate induces lateral displacements and strains in the graphene layer. The displacements lead to the appearance of commensurate regions and the existence of an…

It is significant to prepare large area of high quality graphene for the study of the characteristics of graphene and the research of the nano-devices based on graphene. This paper summarizes the experiment progresses and mechanism of…

We analyze the scattering sector of the Hamiltonians for both gapless and gapped graphene in the presence of a charge impurity using the 2D Dirac equation, which is applicable in the long wavelength limit. We show that for certain range of…

We consider a non-compact Riemannian periodic manifold such that the corresponding Laplacian has a spectral gap. By continuously perturbing the periodic metric locally we can prove the existence of eigenvalues in a gap. A lower bound on the…

Given a rational elliptic surface X over an algebraically closed field, we investigate whether a given natural number k can be the intersection number of two sections of X. If not, we say that k a gap number. We try to answer when gap…

We studied the effect of quantum confinement on the size of the band gap in single layer epitaxial graphene. Samples with different graphene terrace sizes are studied by using low energy electron microscopy (LEEM) and angle-resolved…