scholarly journals Квантовые осцилляции релаксации фотопроводимости в p-i-n-гетеродиодах GaAs/InAs/AlAs

2018 ◽  
Vol 52 (6) ◽  
pp. 591
Author(s):  
Ю.Н. Ханин ◽  
Е.Е. Вдовин
Keyword(s):  
Magnetic Field ◽  
Quantum Well ◽  
Oscillation Amplitude ◽  
Light Flux ◽  
Quantum Oscillations ◽  
Ballistic Motion ◽  
The Common ◽  
Relaxation Curves ◽  
Relaxation Characteristics ◽  
The Magnetic Field

AbstractThe photoconductivity and its relaxation characteristics in tunneling p – i – n GaAs/AlAs heterostructures under pulsed illumination is studied. Quantum oscillations in the photoconductivity are detected depending on the bias voltage with the period independent of the light wavelength, as well as an oscillating component of the relaxation curves caused by modulation of the recombination rate at the edge of a triangular quantum well in the undoped i layer, as in the case of photoconductivity oscillations. The common nature of oscillations of the steady-state photoconductivity and relaxation curves under pulsed illumination is directly confirmed by the lack of an oscillating component in both types of dependences of some studied p–i–n heterostructures. Simultaneous suppression of the observed oscillations of dependences of both types as the temperature increases to 80 K also confirms the proposed mechanism of their formation. The dependences of these oscillations on the magnetic field and light flux power are studied. Oscillation-amplitude suppression in a magnetic field of ~2 T perpendicular to the current is caused by the effect of the Lorentz force on the ballistic motion of carriers in the triangular-quantum-well region.

Theoretical Investigation of the Shubnikov-de Haas Magnetoresistance Oscillations in a Quantum well under the Influence of Confined Acoustic Phonons

2018 ◽  
Vol 783 ◽  
pp. 1-11
Author(s):  
Le Thai Hung ◽  
Pham Ngoc Thang ◽  
Nguyen Quang Bau
Keyword(s):  
Magnetic Field ◽  
Quantum Well ◽  
Phonon Confinement ◽  
Acoustic Phonons ◽  
Magnetic Impedance ◽  
Magnetoresistance Oscillations ◽  
The Magnetic Field ◽  
Amplitude Decrease ◽  
Theoretical Results ◽  
Phonon Confinement Effect

The Shubnikov – de Haas magnetoresistance oscillations in the Quantum well (QW) under the influence of confined acoustic phonons, The theoretical results show that the conductivity tensor, the complex magnetic impedance of the magnetic field, the frequency, the amplitude of the laser radiation, the QW width, the temperature of the system and especially the quantum index m characterizes the confinement of the phonon. The amplitude of the oscillations of the Shubnikov-de Haas impedance decreases with the increase of the influence of the confined acoustic phonons. The results for bulk phonons in a QW could be achieved, when m goes to zero. We has been compared with other studies when perform the numerical calculations are also achieved for the GaAs/AlGaAs in the QW. Results show that The Shubnikov-de Haas magnetoresistance oscillations amplitude decrease when phonon confinement effect increasing and when width L of the QW increases to a certain value, The Shubnikov – de Haas magnetoresistance oscillations amplitude completely disappears can not be observed.

The effect of nitrogen on the diamagnetic susceptibility of a donor in quantum well under the magnetic field

2010 ◽  
Vol 48 (3) ◽  
pp. 305-311 ◽  
Author(s):  
E. Kilicarslan ◽  
S. Şakiroglu ◽  
E. Kasapoglu ◽  
H. Sari ◽  
I. Sökmen
Keyword(s):  
Magnetic Field ◽  
Quantum Well ◽  
Diamagnetic Susceptibility ◽  
The Magnetic Field

Electron Subband Levels of n-Type δ-Doped Quantum Wells under In-Plane Magnetic Fields

1997 ◽  
Vol 11 (09) ◽  
pp. 1195-1207
Author(s):  
E. K. Takahashi ◽  
A. T. Lino ◽  
L. M. R. Scolfaro
Keyword(s):  
Magnetic Field ◽  
Electronic Structure ◽  
Magnetic Fields ◽  
Quantum Well ◽  
Quantum Wells ◽  
Conduction Band ◽  
Electron Energy ◽  
Self Consistent ◽  
Plane Direction ◽  
The Magnetic Field

Self-consistent calculations of the electronic structure of center n-δ-doped GaAs/Al x Ga 1-x As quantum wells under in-plane magnetic fields are presented. The field B is varied up to 20 Tesla for different quantum well widths L w and sheet donor concentrations N D . The magnetic field produces noticeable changes in the energy dispersions along an in-plane direction perpendicular to B. The effects of B are more pronounced for higher electronic subbands. It is found that the diamagnetic shifts increase with increasing L w and/or N D . Contrarily to what has been observed in modulation-doped quantum wells, in these δ-doped systems the electron energy dispersions keep the single conduction band minimum at the center of the Brillouin zone even for intense magnetic fields.

Scattering Processes with the Emission of Longitudinal Optical Phonons in the Landau Level System In GaAs/AlGaAs Quantum Well

2021 ◽  
Author(s):  
Ngo Vinh Doan The ◽  
Trung Le Canh
Keyword(s):  
Magnetic Field ◽  
Quantum Well ◽  
Quantum Wells ◽  
Golden Rule ◽  
Longitudinal Optical ◽  
Optical Phonons ◽  
Scattering Rate ◽  
Quantizing Magnetic Field ◽  
Scattering Time ◽  
The Magnetic Field

Abstract The scattering processes of longitudinal optical phonons in GaAs/AlGaAs quantum wells in a quantizing magnetic field are considered. The time of intrasubband scattering between Landau levels is calculated by using Fermi's golden rule. The dependence of the scattering rate on the magnitude of the magnetic field has been shown and the magnetic field can suppress scattering processes on longitudinal optical phonons. It is found that the scattering time depends linearly on the width of the quantum well.

scholarly journals On the field of force near the neutral point produced by two equal coaxial coils, with special reference to the Campbell standard of mutual inductance

1925 ◽  
Vol 107 (744) ◽  
pp. 716-724 ◽  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Special Reference ◽  
Opposite Direction ◽  
Mutual Inductance ◽  
Common Axis ◽  
The Common ◽  
Small Change ◽  
The Magnetic Field ◽  
A Current

When a current is passed through two equal coaxial coils so that the component of the magnetic fields parallel to the common axis add, there is a circle, mid-way between the two coils, at which the magnetic field is zero. At all points in the plane of that circle lying outside it, the field of force is in one direction, and at all points within the circle it is in the opposite direction. It is evident, therefore, that if a coaxial turn of wire be placed in the plane of the circle, the mutual inductance between the two coils will be a maximum, when the wire coincides with the circle, and any small change in the radius of the turn will affect the value of the mutual inductance only to the second order of small quantities.

High Field Magnetoacoustic Investigation of the Fermi Surface of Tungsten

1973 ◽  
Vol 51 (1) ◽  
pp. 77-86 ◽  
Author(s):  
J. P. Kalejs ◽  
J. M. Perz
Keyword(s):  
Magnetic Field ◽  
Fermi Surface ◽  
Empirical Model ◽  
Cyclotron Resonance ◽  
High Field ◽  
Ultrasonic Waves ◽  
Quantum Oscillations ◽  
Resonance Data ◽  
The Magnetic Field ◽  
Longitudinal Ultrasonic Waves

We have measured the frequencies of quantum oscillations in the attenuation of 20 MHz longitudinal ultrasonic waves in tungsten in magnetic fields up to 109 kOe. Our results agree well with the de Haas–van Alphen (dHvA) data of Girvan, Gold, and Phillips (GGP). In addition, we see features predicted by the empirical model developed by GGP but not observed directly in the dHvA studies. Specifically, we find strong evidence of the continuation of the ω branch (GGP notation) for the magnetic field H in the [Formula: see text] plane right to the [110] direction; we also observe splitting of the ξ branch for field directions near [111], but not to the extent predicted by the model. From the temperature dependence of the amplitudes of the quantum oscillations, we have deduced cyclotron masses for some orbits; these agree well with GGP and cyclotron resonance data.

scholarly journals Magneto – thermoelectric effects in quantum well in the presence of electromagnetic wave

2017 ◽  
Vol 33 (2) ◽  
Author(s):  
Nguyen Quang Bau ◽  
Dao Thu Hang ◽  
Doan Minh Quang ◽  
Nguyen Thi Thanh Nhan
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Wave ◽  
Quantum Well ◽  
Quantum Kinetic Equation ◽  
Thermoelectric Effects ◽  
Parabolic Potential ◽  
Bulk Semiconductors ◽  
Sdh Oscillations ◽  
Analytic Expression ◽  
The Magnetic Field

Abstract. We have studied magneto-thermoelectric effects in quantum well in the presence of electromagnetic wave. The analytic expression for Ettingshausen coefficient (EC) in the Quantum Well with parabolic potential (QWPP) in the presence of Electromagnetic wave (EMW) is calculated by using the quantum kinetic equation for electrons. The dependence of EC on the frequency, the amplitude of EMW, the Quantum Well parameters and the temperature are obtained. The results are numerically calculated, plotted, and discussed for GaAs/GaAsAl Quantum Well to clearly show the dependence of EC on above parameters and the results in this case are compared with the case in the bulk semiconductors. We realize that as the temperature increases, the EC decreases. The results show appearance of the Shubnikov–de Haas (SdH) oscillations when we survey the dependence of EC on the magnetic field.  Keywords:  Ettingshausen, Quantum well, Electromagnetic wave, parabolic potential, GaAs/GaAsAl.

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