The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
A. L. Rakhmanov - One of the best experts on this subject based on the ideXlab platform.
-
Spin-density wave state in simple Hexagonal Graphite
Physical Review B, 2018Co-Authors: K. S. Mosoyan, A. V. Rozhkov, A. O. Sboychakov, A. L. RakhmanovAbstract:Simple Hexagonal Graphite, also known as AA Graphite, is a metastable configuration of Graphite. Using tight-binding approximation, it is easy to show that AA Graphite is a metal with well-defined Fermi surface. The Fermi surface consists of two sheets, each shaped like a rugby ball. One sheet corresponds to electron states, another corresponds to hole states. The Fermi surface demonstrates good nesting: a suitable translation in the reciprocal space superposes one sheet onto another. In the presence of the electron-electron repulsion, a nested Fermi surface is unstable with respect to spin-density-wave ordering. This instability is studied using the mean-field theory at zero temperature, and the spin-density-wave order parameter is evaluated.
-
Spin-density wave in simple Hexagonal Graphite
arXiv: Strongly Correlated Electrons, 2017Co-Authors: K. S. Mosoyan, A. V. Rozhkov, A. O. Sboychakov, A. L. RakhmanovAbstract:Simple Hexagonal Graphite, also known as AA Graphite, is a metastable configuration of Graphite. Using tight-binding approximation it is easy to demonstrate that AA Graphite is a metal with well-defined Fermi surface. The Fermi surface consists of two sheets, each shaped like a rugby ball. One sheet corresponds to electron states, another corresponds to hole states. The Fermi surface demonstrates good nesting: a suitable translation in the reciprocal space superposes one sheet onto another. In the presence of the electron-electron repulsion a nested Fermi surface is unstable with respect to spin-density wave ordering. This instability is studied using the mean-field theory at zero temperature, and the spin-density wave order parameter is evaluated.
Manuel Richter - One of the best experts on this subject based on the ideXlab platform.
-
Electronic structure of stacking faults in Hexagonal Graphite
Physical Review B, 2013Co-Authors: M. Taut, Klaus Koepernik, Manuel RichterAbstract:We present results of self-consistent, full-potential electronic structure calculations for slabs of Hexagonal Graphite with stacking faults and for slabs with one displaced surface layer. There are two types of stacking faults, which differ qualitatively in their chemical bonding picture. We find, that both types induce localized interface bands near the symmetry line K-M in the Brillouin zone and a related peak in the local density of states (LDOS) very close to the Fermi energy, which should give rise to a dominating contribution of the interface bands to the local conductivity at the stacking faults. In contrast, a clean surface does not host any surface bands in the energy range of the pi and sigma bands, and the LDOS near the surface is even depleted. On the other hand, displacement of even one single surface layer induces a surface band near K-M. A special role play p_z-bonded dimers (directed perpendicular to the layers) in the vicinity of one type of stacking faults. They produce a half-filled pair of interface states / interface resonances. The formation energy of both types of stacking faults and the surface energy are estimated.
K. S. Mosoyan - One of the best experts on this subject based on the ideXlab platform.
-
Spin-density wave state in simple Hexagonal Graphite
Physical Review B, 2018Co-Authors: K. S. Mosoyan, A. V. Rozhkov, A. O. Sboychakov, A. L. RakhmanovAbstract:Simple Hexagonal Graphite, also known as AA Graphite, is a metastable configuration of Graphite. Using tight-binding approximation, it is easy to show that AA Graphite is a metal with well-defined Fermi surface. The Fermi surface consists of two sheets, each shaped like a rugby ball. One sheet corresponds to electron states, another corresponds to hole states. The Fermi surface demonstrates good nesting: a suitable translation in the reciprocal space superposes one sheet onto another. In the presence of the electron-electron repulsion, a nested Fermi surface is unstable with respect to spin-density-wave ordering. This instability is studied using the mean-field theory at zero temperature, and the spin-density-wave order parameter is evaluated.
-
Spin-density wave in simple Hexagonal Graphite
arXiv: Strongly Correlated Electrons, 2017Co-Authors: K. S. Mosoyan, A. V. Rozhkov, A. O. Sboychakov, A. L. RakhmanovAbstract:Simple Hexagonal Graphite, also known as AA Graphite, is a metastable configuration of Graphite. Using tight-binding approximation it is easy to demonstrate that AA Graphite is a metal with well-defined Fermi surface. The Fermi surface consists of two sheets, each shaped like a rugby ball. One sheet corresponds to electron states, another corresponds to hole states. The Fermi surface demonstrates good nesting: a suitable translation in the reciprocal space superposes one sheet onto another. In the presence of the electron-electron repulsion a nested Fermi surface is unstable with respect to spin-density wave ordering. This instability is studied using the mean-field theory at zero temperature, and the spin-density wave order parameter is evaluated.
Ming-fa Lin - One of the best experts on this subject based on the ideXlab platform.
-
Beating oscillations of magneto-optical spectra in simple Hexagonal Graphite
Computer Physics Communications, 2015Co-Authors: Rong Bin Chen, Yu Huang Chiu, Ming-fa LinAbstract:The magneto-optical properties of simple Hexagonal Graphite exhibit rich beating oscillations, which are dominated by the field strength and photon energy. The former has a strong effect on the intensity, the energy range of the beating and the number of groups, and the latter modulates the total group numbers of the oscillation structures. The single-particle and collective excitations are simultaneously presented in the magnetoreflectance spectra and can be precisely distinguished. For the loss function and reflectance, the beating pattern of the first group displays stronger intensities and broader energy range than other groups. Simple Hexagonal Graphite possesses unique magneto-optical characteristics that can serve to identify other bulk Graphites.
-
Magnetoplasmons in simple Hexagonal Graphite
RSC Advances, 2015Co-Authors: Rong Bin Chen, Chih Wei Chiu, Ming-fa LinAbstract:Magneto-electronic Coulomb excitations in simple Hexagonal Graphite (SHG) are studied within the random-phase approximation. They strongly depend on the direction and the magnitude of the transferred momentum q, and the magnetic field strength. The plasmon frequency dispersion in the perpendicular component qz in the primitive unit cell and its parallel component q‖ are very different from each other. The former shows only one prominent peak. The plasmon frequency increases with qz, while the intensity of the plasmon peak exhibits the opposite behavior. The latter presents many plasmon peaks. Moreover, the threshold frequency of the loss spectrum for SHG is higher than that of monolayer graphene. As the field strength increases, the plasmon peaks are intensified. The group velocity for plasmon propagation along is typically positive for a fixed field strength. The qz-dependence of the plasmon frequency is gradually reduced with an increased field strength. Graphite somewhat differs from graphene in magneto-electronic excitations, including the intensity, number and frequency of magnetoplasmons.
-
Electronic Thermal Property of Graphite
Journal of the Physical Society of Japan, 2013Co-Authors: Shih-yang Lin, Feng-lin Shyu, Ming-fa LinAbstract:The interlayer atomic interactions determine the low-lying band structure of Graphite and thus the electronic specific heat. Simple Hexagonal Graphite presents the greatest specific heat and exhibits a linear temperature-dependence due to the nearly constant density of states. Bernal Graphite deviates from the linear \(T\)-dependence as temperature is above 100 K. Rhombohedral Graphite shows the linear dependence only in the low temperature range, and is revealed to have the lowest specific heat. In addition, monolayer graphene has a \(T\)-square dependence. These significant differences in thermal property originate from the stacking symmetry.
-
Low-Frequency π-Electronic Excitations of Simple Hexagonal Graphite
Journal of the Physical Society of Japan, 2001Co-Authors: Feng-lin Shyu, Ming-fa LinAbstract:The simple Hexagonal Graphite exhibits novel excitation properties. The low-frequency π-electronic excitations principally reflect the π-band characteristics, the strong wave-vector-dependence, the highly anisotropic behavior, and the special symmetry. The plasmon frequency increases with momentum, while the opposite is true for the intensity of plasmon peak. The low-frequency plasmon behaves as the optical plasmon in a 3D electron gas. The main differences between plasmons parallel and perpendicular to the Graphite planes are very special. The former have higher plasmon frequencies. However, their plasmon peaks and critical momenta are much lower than those of the latter. Doping leads to significant changes in the π-electronic excitations, such as the great enhancement of plasmon frequency and plasmon peak. The electronic excitations of the simple Hexagonal Graphite quite differ from those in the Bernal Graphite or the 2D Graphite sheet.
A. V. Rozhkov - One of the best experts on this subject based on the ideXlab platform.
-
Spin-density wave state in simple Hexagonal Graphite
Physical Review B, 2018Co-Authors: K. S. Mosoyan, A. V. Rozhkov, A. O. Sboychakov, A. L. RakhmanovAbstract:Simple Hexagonal Graphite, also known as AA Graphite, is a metastable configuration of Graphite. Using tight-binding approximation, it is easy to show that AA Graphite is a metal with well-defined Fermi surface. The Fermi surface consists of two sheets, each shaped like a rugby ball. One sheet corresponds to electron states, another corresponds to hole states. The Fermi surface demonstrates good nesting: a suitable translation in the reciprocal space superposes one sheet onto another. In the presence of the electron-electron repulsion, a nested Fermi surface is unstable with respect to spin-density-wave ordering. This instability is studied using the mean-field theory at zero temperature, and the spin-density-wave order parameter is evaluated.
-
Spin-density wave in simple Hexagonal Graphite
arXiv: Strongly Correlated Electrons, 2017Co-Authors: K. S. Mosoyan, A. V. Rozhkov, A. O. Sboychakov, A. L. RakhmanovAbstract:Simple Hexagonal Graphite, also known as AA Graphite, is a metastable configuration of Graphite. Using tight-binding approximation it is easy to demonstrate that AA Graphite is a metal with well-defined Fermi surface. The Fermi surface consists of two sheets, each shaped like a rugby ball. One sheet corresponds to electron states, another corresponds to hole states. The Fermi surface demonstrates good nesting: a suitable translation in the reciprocal space superposes one sheet onto another. In the presence of the electron-electron repulsion a nested Fermi surface is unstable with respect to spin-density wave ordering. This instability is studied using the mean-field theory at zero temperature, and the spin-density wave order parameter is evaluated.