Topic

# Fermi level

About: Fermi level is a research topic. Over the lifetime, 27191 publications have been published within this topic receiving 652441 citations.

##### Papers published on a yearly basis

##### Papers

More filters

••

[...]

TL;DR: In this article, the authors focus on the origin of the D and G peaks and the second order of D peak and show that the G and 2 D Raman peaks change in shape, position and relative intensity with number of graphene layers.

Abstract: We review recent work on Raman spectroscopy of graphite and graphene. We focus on the origin of the D and G peaks and the second order of the D peak. The G and 2 D Raman peaks change in shape, position and relative intensity with number of graphene layers. This reflects the evolution of the electronic structure and electron–phonon interactions. We then consider the effects of doping on the Raman spectra of graphene. The Fermi energy is tuned by applying a gate-voltage. We show that this induces a stiffening of the Raman G peak for both holes and electrons doping. Thus Raman spectroscopy can be efficiently used to monitor number of layers, quality of layers, doping level and confinement.

5,730 citations

••

[...]

TL;DR: In this paper, a compilation of all published measurements of electron inelastic mean free path lengths in solids for energies in the range 0-10 000 eV above the Fermi level is presented.

Abstract: A compilation is presented of all published measurements of electron inelastic mean free path lengths in solids for energies in the range 0–10 000 eV above the Fermi level. For analysis, the materials are grouped under one of the headings: element, inorganic compound, organic compound and adsorbed gas, with the path lengths each time expressed in nanometers, monolayers and milligrams per square metre. The path lengths are vary high at low energies, fall to 0.1–0.8 nm for energies in the range 30–100 eV and then rise again as the energy increases further. For elements and inorganic compounds the scatter about a ‘universal curve’ is least when the path lengths are expressed in monolayers, λm. Analysis of the inter-element and inter-compound effects shows that λm is related to atom size and the most accuratae relations are λm = 538E−2+0.41(aE)1/2 for elements and λm=2170E−2+0.72(aE)1/2 for inorganic compounds, where a is the monolayer thickness (nm) and E is the electron energy above the Fermi level in eV. For organic compounds λd=49E−2+0.11E1/2 mgm−2. Published general theoretical predictions for λ, valid above 150 eV, do not show as good correlations with the experimental data as the above relations.

4,300 citations

••

[...]

Philips

^{1}TL;DR: The band structure of Mn-based Heusler alloys of the crystal structure (MgAgAs type) has been calculated with the augmented-spherical-wave method.

Abstract: The band structure of Mn-based Heusler alloys of the $C{1}_{b}$ crystal structure (MgAgAs type) has been calculated with the augmented-spherical-wave method. Some of these magnetic compounds show unusual electronic properties. The majority-spin electrons are metallic, whereas the minority-spin electrons are semiconducting.

3,442 citations

••

[...]

TL;DR: The results establish that Bi2Te3 is a simple model system for the three-dimensional topological insulator with a single Dirac cone on the surface, and points to promising potential for high-temperature spintronics applications.

Abstract: Three-dimensional topological insulators are a new state of quantum matter with a bulk gap and odd number of relativistic Dirac fermions on the surface. By investigating the surface state of Bi2Te3 with angle-resolved photoemission spectroscopy, we demonstrate that the surface state consists of a single nondegenerate Dirac cone. Furthermore, with appropriate hole doping, the Fermi level can be tuned to intersect only the surface states, indicating a full energy gap for the bulk states. Our results establish that Bi2Te3 is a simple model system for the three-dimensional topological insulator with a single Dirac cone on the surface. The large bulk gap of Bi2Te3 also points to promising potential for high-temperature spintronics applications.

2,499 citations

••

[...]

TL;DR: In this article, the electronic states of graphite ribbons with edges of two typical shapes, armchair and zigzag, were studied by performing tight binding band calculations, and it was shown that the graphite ribbon showed striking contrast in the electronic state depending on the edge shape.

Abstract: We study the electronic states of graphite ribbons with edges of two typical shapes, armchair and zigzag, by performing tight binding band calculations, and find that the graphite ribbons show striking contrast in the electronic states depending on the edge shape. In particular, a zigzag ribbon shows a remarkably sharp peak of density of states at the Fermi level, which does not originate from infinite graphite. We find that the singular electronic states arise from the partly flat bands at the Fermi level, whose wave functions are mainly localized on the zigzag edge. We reveal the puzzle for the emergence of the peculiar edge state by deriving the analytic form in the case of semi-infinite graphite with a zigzag edge. Applying the Hubbard model within the mean-field approximation, we discuss the possible magnetic structure in nanometer-scale micrographite.

2,296 citations