scholarly journals Effect of optical phonon on magnetic excitation of two-dimensional Heisenberg ferromagnetic system

2006 ◽  
Vol 55 (6) ◽  
pp. 2941
Author(s):  
Cheng Tai-Min ◽  
Xianyu Ze ◽  
Gang Tie-Chen
Keyword(s):  
Optical Phonon ◽  
Magnetic Excitation ◽  
Two Dimensional ◽  
Ferromagnetic System

scholarly journals Extremely low-frequency phonon material and its temperature- and photo-induced switching effects

2020 ◽  
Vol 11 (33) ◽  
pp. 8989-8998
Author(s):  
Takaya Yoshida ◽  
Koji Nakabayashi ◽  
Hiroko Tokoro ◽  
Marie Yoshikiyo ◽  
Asuka Namai ◽  
...  
Keyword(s):  
Optical Phonon ◽  
Phonon Mode ◽  
Low Frequency ◽  
Switching Effect ◽  
Two Dimensional ◽  
Optical Phonon Mode ◽  
Extremely Low Frequency

Extremely low-frequency optical phonon mode in Rb-intercalated two-dimensional cyanide-bridged Co–W bimetal assembly and its temperature- and photo-induced switching effect.

scholarly journals Magnetic dynamo action in two-dimensional turbulent magneto-hydrodynamics

1977 ◽  
Vol 17 (2) ◽  
pp. 317-335 ◽  
Author(s):  
David Fyfe ◽  
Glenn Joyce ◽  
David Montgomery
Keyword(s):  
Initial Conditions ◽  
Magnetic Energy ◽  
Field Energy ◽  
Magnetic Excitation ◽  
External Forcing ◽  
Two Dimensional ◽  
Dynamo Action ◽  
Magnetohydrodynamic Turbulence ◽  
Long Wavelength ◽  
Magnetic Field Energy

Two-dimensional magnetohydrodynamic turbulence is explored by means of numerical simulation. Previous analytical theory, based on non-dissipative constants of the motion in a truncated Fourier representation, is verified by following the evolution of highly non-equilibrium initial conditions numerically. Dynamo action (conversion of a significant fraction of turbulent kinetic energy into long-wavelength magnetic field energy) is observed. It is conjectured that in the presence of dissipation and external forcing; a dual cascade will be observed for zero-helicity situations. Energy will cascade to higher wavenumbers simultaneously with a cascade of mean square vector potential to lower wavenumbers, leading to an omni-directional magnetic energy spectrum which varies as k-⅓ at lower wavenumbers, simultaneously with a build-up of magnetic excitation at the lowest wavenumber of the system. Equipartition of kinetic and magnetic energies is expected at the highest wavenumbers in the system.

Origin of phonon-limited mobility in two-dimensional metal dichalcogenides

2021 ◽  
Vol 34 (1) ◽  
pp. 013003
Author(s):  
Hao Chang ◽  
Hao Wang ◽  
Ke-Ke Song ◽  
Min Zhong ◽  
Li-Bin Shi ◽  
...  
Keyword(s):  
Optical Phonon ◽  
Transport Theory ◽  
Coupling Effect ◽  
Dielectric Constants ◽  
Polar Optical Phonon ◽  
Two Dimensional ◽  
Limited Mobility ◽  
Boltzmann Transport Theory ◽  
2D Semiconductors ◽  
Metal Dichalcogenides

Abstract Metal dichalcogenides are novel two-dimensional (2D) semiconductors after the discovery of graphene. In this article, phonon-limited mobility for six kinds of 2D semiconductors with the composition of MX2 is reviewed, in which M (Cr, Mo and W) is the transition metal, and X (S and Se) is the chalcogen element. The review is divided into three parts. In the first part, we briefly introduce the calculation method of mobility, including the empirical model and Boltzmann transport theory (BTE). The application scope, merits and limitations of these methods are summarized. In the second part, we explore empirical models to calculate the mobility of MX2, including longitudinal acoustic phonon, optical phonon (OP) and polar optical phonon (POP) models. The contribution of multi-valley to mobility is reviewed in the calculation. The differences between static and high-frequency dielectric constants (Δϵ) are only 0.13 and 0.03 for MoS2 and WS2. Such a low value indicates that the polarization hardly changes in the external field. So, their mobility is not determined by POP, but by deformation potential models. Different from GaAs, POP scattering plays a decisive role in its mobility. Our investigations also reveal that the scattering from POP cannot be ignored in CrSe2, MoSe2 and WSe2. In the third parts, we investigate the mobility of MX2 using electron–phonon coupling matrix element, which is based on BTE from the framework of a many-body quantum-field theory. Valence band splitting of MoS2 and WS2 is induced by spin–orbit coupling effect, which leads to the increase of hole mobility. In particular, we review in detail the theoretical and experimental results of MoS2 mobility in recent ten years, and its mobility is also compared with other materials to deepen the understanding.

Monte Carlo Simulation of Magnetization Recovery in Two-Dimensional Ferromagnetic System after Ultrafast Pump Pulses

2012 ◽  
Vol 51 (12R) ◽  
pp. 123001
Author(s):  
WenXiao Fang ◽  
YunFei En ◽  
Bin Zhou ◽  
QinWen Huang ◽  
Xin Liu ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Two Dimensional ◽  
Ferromagnetic System

scholarly journals Two-dimensional resonant magnetic excitation inBaFe1.84Co0.16As2

2009 ◽  
Vol 102 (10) ◽  
Author(s):  
M. D. Lumsden ◽  
A. D. Christianson ◽  
D. Parshall ◽  
M. B. Stone ◽  
S. E. Nagler ◽  
...  
Keyword(s):  
Magnetic Excitation ◽  
Two Dimensional
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