scholarly journals THE ANOMALOUS METALLIC FERROMAGNETIC STATE OF Sr DOPED MANGANITES

2001 ◽  
Vol 15 (23) ◽  
pp. 1031-1040 ◽  
Author(s):  
V. FERRARI ◽  
M. J. ROZENBERG ◽  
R. WEHT
Keyword(s):  
Density Of States ◽  
Optical Conductivity ◽  
Low Temperatures ◽  
Ferromagnetic State ◽  
Ferromagnetic Phase ◽  
Metallic State ◽  
Natural Explanation ◽  
Doped Manganites

We deduce a model relevant for the anomalous metallic state of Sr doped manganites at low temperatures within the ferromagnetic phase. It provides a natural explanation for several anomalous features observed experimentally, such as the small Drude contribution in optical conductivity, the "pseudo-gap" in the density of states, and the unusual dispersion observed in photoemission.

Optical Properties of the Half-Metallic La3/4Ca1/4MnO3

1998 ◽  
Vol 12 (29n31) ◽  
pp. 3359-3364
Author(s):  
D. Bagayoko ◽  
G. L. Zhao ◽  
J. D. Fan ◽  
J. T. Wang
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Optical Conductivity ◽  
Local Density ◽  
Metallic Phase ◽  
Ferromagnetic Phase ◽  
Metallic State ◽  
Average Magnetic Moment ◽  
Half Metallic ◽  
Experimental Values

We studied the electronic structure and optical properties of the low temperature (T = 0 K for the calculation) ferromagnetic phase of La3/4Ca1/4MnO3 using a self-consistent ab-initio LCAO method. We employed a local density potential. The calculated electronic structure suggests that the material is in a half-metallic state. The calculated average magnetic moment for the half-metallic phase is 3.75 μ B per Mn. This value is very close to the experimental values of 3.7 μ B per Mn. The real part of the optical conductivity, σ1(ω), from the direct band transitions, is predicted. The calculated optical conductivity shows that for photon energies below 2.4 eV, the electronic states of minority spin do not contribute to the optical transitions.

scholarly journals Low-Energy Optical Conductivity of TaP: Comparison of Theory and Experiment

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 567
Author(s):  
Alexander Yaresko ◽  
Artem V. Pronin
Keyword(s):  
Experimental Data ◽  
Optical Conductivity ◽  
Low Energy ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Natural Explanation ◽  
Weyl Semimetal ◽  
Unintentional Doping ◽  
Mott Formula ◽  
Theory And Experiment

The ab-plane optical conductivity of the Weyl semimetal TaP is calculated from the band structure and compared to the experimental data. The overall agreement between theory and experiment is found to be best when the Fermi level is slightly (20 to 60 meV) shifted upwards in the calculations. This confirms a small unintentional doping of TaP, reported earlier, and allows a natural explanation of the strong low-energy (50 meV) peak seen in the experimental ab-plane optical conductivity: this peak originates from transitions between the almost parallel non-degenerate electronic bands split by spin-orbit coupling. The temperature evolution of the peak can be reasonably well reproduce by calculations using an analog of the Mott formula.

A Monte Carlo simulation of steady state of 2D Ising model in temperature field

2016 ◽  
Vol 30 (04) ◽  
pp. 1650022 ◽  
Author(s):  
Zeshun Chen ◽  
Changming Xiao ◽  
Zhen Yao
Keyword(s):  
Monte Carlo ◽  
Temperature Field ◽  
Steady State ◽  
Ising Model ◽  
Low Temperatures ◽  
Ferromagnetic State ◽  
Model System ◽  
Local Magnetization ◽  
New Energy ◽  
High And Low Temperatures

Supposing the Ising model system is placed in a temperature field with constant high and low temperatures on both sides, then the system will shift to a non-equilibrium steady state with a certain temperature gradient. With the assistance of local temperature, the steady state of two-dimensional Ising model is studied via the avenue of Monte Carlo simulations in this paper. It is found that the local energy and magnetization are continuous, but there is a sharp decline in the magnetization strength when the temperature falls into the range of 2.2–2.4. The local magnetization [Formula: see text], when the temperature [Formula: see text]. It is the indication that the system is in the ferromagnetic state. However, when [Formula: see text], [Formula: see text], and then the ferromagnetic state turns into the paramagnetic state. Furthermore, a completely new and special state of Ising model system and the corresponding material is possible if the high and low temperatures of the temperature field are larger and smaller than the critical value of the system, respectively. According to this material, the magnetic driving machine, from which a new energy source can be obtained, is qualitatively discussed at the end of this paper.

Neutron lifetime and density of states of fluoropolymers at low temperatures

JETP Letters ◽  
2017 ◽  
Vol 105 (8) ◽  
pp. 548-551 ◽  
Author(s):  
E. A. Goremychkin ◽  
Yu. N. Pokotilovski
Keyword(s):  
Density Of States ◽  
Low Temperatures ◽  
Neutron Lifetime

Stabilisation of the metallic state at low temperatures in HMTTF-TCNQ under pressure

1978 ◽  
Vol 11 (2) ◽  
pp. 263-275 ◽  
Author(s):  
R H Friend ◽  
D Jerome ◽  
J M Fabre ◽  
L Giral ◽  
K Bechgaard
Keyword(s):  
Low Temperatures ◽  
Metallic State

Optical Absorptions in Metal Sodium: The Temperature Dependence in the Liquid State

1974 ◽  
Vol 29 (3) ◽  
pp. 462-468
Author(s):  
N. C. Haider
Keyword(s):  
Perturbation Theory ◽  
Solid State ◽  
Temperature Dependence ◽  
Electron Density ◽  
Electron Energy ◽  
Density Of States ◽  
Optical Conductivity ◽  
Liquid State ◽  
Present Calculation ◽  
Electron Density Of States

The temperature dependence of optical absorptions in liquid Na is calculated. The electron energy values are obtained to second order in perturbation theory which are then used to determine the electron density of states. The density of states plots show some structure similar to those noted in the solid state. The optical conductivity in the liquid state is found to increase with the temperature as in the solid state. The present calculation for the optical conductivity gives a rather sharp peak around ħ ω = 1.7 eV. These results are in better agreement with the existing experimental results

Formation and Electronic Structure of the Mn/GaAs(100) Interface

1992 ◽  
Vol 281 ◽  
Author(s):  
X. Jin ◽  
M. Zhang ◽  
G. S. Dong ◽  
Z. S. Li ◽  
Xun Wang ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Electron Density ◽  
Density Of States ◽  
Room Temperature ◽  
Early Stage ◽  
Ferromagnetic Phase ◽  
Two Dimensional ◽  
Interface Diffusion ◽  
Electron Density Of States ◽  
Fermi Edge

ABSTRACTFormation and electronic structure of the Mn/GaAs(100) interface grown at room temperature are studied by photoemission. The growth at early stage is identified to be in two-dimensional mode. The chemical reaction and the interface diffusion happened between Mn and GaAs are explored in some details. A ferromagnetic phase of Mn overlayer at early stage is deduced from the change of electron density of states near the Fermi edge.

Sign in / Sign up

Export Citation Format

Share Document