The magnetic field dependence of the deformation potential materials in the square well confinement potential

Open Physics ◽  
2008 ◽  
Vol 6 (4) ◽  
Author(s):  
Joung Sug ◽  
Su Lee ◽  
Jong Kim
Keyword(s):  
Magnetic Field ◽  
Landau Level ◽  
Transition Process ◽  
Quantum Transition ◽  
Transition Line ◽  
Deformation Potential ◽  
Confinement Potential ◽  
Level Transition ◽  
Square Well ◽  
The Magnetic Field

AbstractWe study the optical Quantum Transition Line Shapes (QTLS) which show the absorption power and the Quantum Transition Line Widths (QTLW) of electron-deformation potential phonon interacting systems. In order to analyze the quantum transition, we compare the magnetic field dependencies of the QTLWand the QTLS on two transition processes, namely the intra-Landau level transition process and the inter-Landau level transition process. We apply the Quantum Transport theory (QTR) to the system in the confinement of electrons by square well confinement potential. We use the projected Liouville equation method with Equilibrium Average Projection Scheme (EAPS).

Properties of Optical Quantum Transition of GaN and CdS In Electron Deformation Potential Phonon Interacting Qusi-Two Dimensional System under Two Circularly Oscillating Fields

2013 ◽  
Vol 547 ◽  
pp. 165-172
Author(s):  
S.H. Lee ◽  
J.Y. Sug ◽  
J.H. Park
Keyword(s):  
Transition Process ◽  
Quantum Transition ◽  
Dimensional System ◽  
Transition Line ◽  
Deformation Potential ◽  
External Fields ◽  
Phonon Interaction ◽  
Line Shapes ◽  
Emission Transition ◽  
Absorption Power

We study optical quantum transition line shapes (QTRSs) and optical quantum transition line widths (QTLWs) in relation to magnetic-field dependence properties of the electron-deformation potential phonon interaction system. We consider two systems - one is subject to right circularly oscillating external fields and the other is subject to left circularly oscillatory external fields. The main purpose of this work is to compare QTLSs, which indicate absorption power, in the two oscillating external fields. Our results indicate that the QTLSs of right circularly oscillating external fields is larger than the QTLSs of left circularly oscillating external fields, while the opposite result is obtained for the QTLWs. Through the analysis of this work , we found the increasing properties of QTLW and QTLS of GaN and CdS with the temperature and the magnetic fields. We also found the dominant scattering processes are the phonon emission transition process.(PACS: 72.10.Bg,72.10.Di)

scholarly journals Effect of confinement potential shape on the electronic, thermodynamic, magnetic and transport properties of a GaAs quantum dot at finite temperature

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
K. Luhluh Jahan ◽  
Bahadir Boyacioglu ◽  
Ashok Chatterjee
Keyword(s):  
Magnetic Field ◽  
Heat Capacity ◽  
Quantum Dot ◽  
Transport Properties ◽  
Average Energy ◽  
Persistent Current ◽  
Confinement Potential ◽  
Potential Shape ◽  
Gaas Quantum Dot ◽  
The Magnetic Field

Abstract The effect of the shape of the confinement potential on the electronic, thermodynamic, magnetic and transport properties of a GaAs quantum dot is studied using the power-exponential potential model with steepness parameter p. The average energy, heat capacity, magnetic susceptibility and persistent current are calculated using the canonical ensemble approach at low temperature. It is shown that for soft confinement, the average energy depends strongly on p while it is almost independent of p for hard confinement. The heat capacity is found to be independent of the shape and depth of the confinement potential at low temperatures and for the magnetic field considered. It is shown that the system undergoes a paramagnetic-diamagnetic transition at a critical value of the magnetic field. It is furthermore shown that for low values of the potential depth, the system is always diamagnetic irrespective of the shape of the potential if the magnetic field exceeds a certain value. For a range of the magnetic field, there exists a window of p values in which a re-entrant behavior into the diamagnetic phase can occur. Finally, it is shown that the persistent current in the present quantum dot is diamagnetic in nature and its magnitude increases with the depth of the dot potential but is independent of p for the parameters considered.

Optimal Growth and Transition to Turbulence in Magnetohydrodynamic Duct Flow

2010 ◽  
Author(s):  
Dmitry Krasnov ◽  
Oleg Zikanov ◽  
Maurice Rossi ◽  
Thomas Boeck
Keyword(s):  
Magnetic Field ◽  
Optimal Growth ◽  
Transition Process ◽  
Finite Amplitude ◽  
Magnetic Reynolds Number ◽  
Transition To Turbulence ◽  
Duct Flow ◽  
Electrically Conducting ◽  
Nonlinear Mechanism ◽  
The Magnetic Field

We consider the flow of an electrically conducting fluid in a duct in the presence of a constant magnetic field perpendicular to the flow. The technologically relevant approximation of small magnetic Reynolds number is adopted. The focus of investigation is on the nonlinear mechanism of transition consisting of transient growth and subsequent breakdown of finite amplitude perturbations. Numerical analysis demonstrates that the strongest growth is experienced by perturbations localized in the sidewall boundary layers parallel to the imposed magnetic field. This result and the direct numerical simulations of the transition process indicate that the commonly accepted picture of the transition in MHD duct based on the numerical and theoretical analysis of the flow in the Hartmann channel is misleading. The flow may become turbulent within the sidewall layers long before the Hartmann layers on the walls perpendicular to the magnetic field are able to sustain nonlinear transition.

Energy Spectrum of Carriers in a Kane-type Semiconductor Anti-wire

2005 ◽  
Vol 60 (8-9) ◽  
pp. 593-598 ◽  
Author(s):  
Seyfettin Çakmak
Keyword(s):  
Magnetic Field ◽  
Energy Spectrum ◽  
Electronic States ◽  
Wire Radius ◽  
Hard Wall ◽  
Cylinder Axis ◽  
Confinement Potential ◽  
Type Semiconductor ◽  
G Value ◽  
The Magnetic Field

The electronic states of a Kane-type semiconductor anti-wire with and without a magnetic field are theoretically investigated. The eigenvalues and eigenstates of Kane’s Hamiltonian are obtained. The calculations are performed for a hard-wall confinement potential, and electronic states are obtained as functions of the magnetic field applied along the cylinder axis. The size dependences of the effective g-value in InSb for electrons and light holes are calculated. The effective g-values of the electrons and light holes decreased with decreasing anti-wire radius.

scholarly journals Cyclotron Line Emission from Accretion onto a Magnetized Neutron Star

1981 ◽  
Vol 93 ◽  
pp. 233-233
Author(s):  
E. E. Salpeter
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Landau Level ◽  
Optical Depth ◽  
Radiative Decay ◽  
Line Emission ◽  
Collisional Excitation ◽  
Magnetic Field Axis ◽  
Cyclotron Line ◽  
The Magnetic Field

For material accreting along the magnetic field axis of a neutron star, electrons are quantized into Landau orbits. Collisional excitation of the first excited Landau level, followed by radiative decay, leads to the emission of a cyclotron line. The expected line is broad, because the optical depth is large, and its shape is difficult to calculate. Redshifts due to the recoil of a scattering electron and blueshifts due to scattering from the infalling accretion column are being calculated by I. Wasserman, as well as the proton stopping length in the presence of a magnetic field.

LANDAU LEVELS AND GEOMETRIC QUANTIZATION

1989 ◽  
Vol 04 (15) ◽  
pp. 3939-3949 ◽  
Author(s):  
J. R. KLAUDER ◽  
E. ONOFRI
Keyword(s):  
Magnetic Field ◽  
Landau Level ◽  
Free Particle ◽  
Geometric Quantization ◽  
Point Of View ◽  
Geometrical Approach ◽  
Higher Dimensional ◽  
Definition Of ◽  
The Magnetic Field ◽  
Quantum Counterpart

The geometrical approach to phase-space quantization introduced by Klauder [KQ] is interpreted in terms of a universal magnetic field acting on a free particle moving in a higher dimensional configuration space; quantization corresponds to freezing the particle to its first Landau level. The Geometric Quantization [GQ] scheme appears as the natural technique to define the interaction with the magnetic field for a particle on a general Riemannian manifold. The freedom of redefining the operators' ordering makes it possible to select that particular definition of the Hamiltonian which is adapted to a specific polarization; in this way the first Landau level acquires the expected degeneracy. This unification with GQ makes it clear how algebraic relations between classical observables are or are not preserved under quantization. From this point of view all quantum systems appear as the low energy sector of a generalized theory in which all classical observables have a uniquely assigned quantum counterpart such that Poisson bracket relations are isomorphic to the commutation relations.

scholarly journals Investigation of Magneto-phonon Resonance in Graphene Monolayers

2017 ◽  
Vol 33 (4) ◽  
Author(s):  
Bui Dinh Hoi
Keyword(s):  
Magnetic Field ◽  
Linear Response ◽  
Resonant Scattering ◽  
Linear Response Theory ◽  
Landau Levels ◽  
Effect Of Temperature ◽  
Perpendicular Magnetic Field ◽  
Dirac Fermions ◽  
Deformation Potential ◽  
The Magnetic Field

In this work, utilising the linear response theory we calculate the magneto conductivity (MC) in graphene monolayers, subjected to a static perpendicular magnetic field. The interaction of Dirac fermions with optical phonon via deformation potential is taken into account at high temperature. The dependence of the MC on the magnetic field shows resonant peaks that describe transitions of electrons between Landau levels via the resonant scattering with optical phonons. The effect of temperature on the MC is also obtained and discussed.

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