scholarly journals Polarization induced interface and electron sheet charges of pseudomorphic ScAlN/GaN, GaAlN/GaN, InAlN/GaN, and InAlN/InN heterostructures

2021 ◽  
Vol 129 (20) ◽  
pp. 204501
Author(s):  
O. Ambacher ◽  
B. Christian ◽  
M. Yassine ◽  
M. Baeumler ◽  
S. Leone ◽  
...  
Keyword(s):  
Electron Sheet

Modulation-doped (AlGa)As/GaAs quantum well structure with high electron sheet density

1989 ◽  
Vol 25 (17) ◽  
pp. 1147
Author(s):  
A.L. Powell ◽  
J.S. Roberts ◽  
P.I. Rockett ◽  
T.J. Foster ◽  
L. Eaves
Keyword(s):  
Quantum Well ◽  
High Electron ◽  
Quantum Well Structure ◽  
Electron Sheet ◽  
Sheet Density

Universal scaling of thin current sheets in space plasma

2021 ◽  
Author(s):  
Helmi Malova ◽  
Lev Zelenyi ◽  
Elena Grigorenko ◽  
Victor Popov ◽  
Eduard Dubinin
Keyword(s):  
Hybrid Approach ◽  
Russian Science ◽  
Current Sheets ◽  
Scale Free ◽  
Universal Scaling ◽  
Magnetic Field Profile ◽  
Electron Sheet ◽  
Nonlinear Character ◽  
Drift Orbits ◽  
Universal Expression

<p>Thin current sheets (TCSs) with thicknesses about ion Larmor radii can play the key role in space; particularly they can store and then explosively release the accumulated free energy. The dynamics of ions moving along quasi-adiabatic trajectories in TCSs is different from one of magnetized electrons following guiding center drift orbits. Due to this property TCSs can be described in a frame of a hybrid approach. The thickness of the super-thin embedded electron sheet remains uncertain because of the scale-free character of magnetized electron motion. We propose a new analytical approach to describe the multilayer TCS and provide the universal expression describing the embedded electron sheet as a function of the cross-sheet transversal coordinate z characterizing TCS. We demonstrated that the unique property of the electron sheet is the nonlinear character of magnetic field profile:  <em>B(z) ~ z <sup>1/3 </sup></em>which conforms excellently with MAVEN observations in the Martian magnetotail. </p><p>This work was supported by the Russian Science Foundation (grant # 20-42-04418).</p><p> </p>

The Fermi surface of barium

1971 ◽  
Vol 322 (1551) ◽  
pp. 509-521 ◽  
Keyword(s):  
Fermi Surface ◽  
Enhancement Factor ◽  
Symmetry Plane ◽  
Structure Calculation ◽  
Band Structure Calculation ◽  
Surfaces Of Revolution ◽  
Mass Measurements ◽  
Electron Sheet ◽  
Cyclotron Mass ◽  
Mass Enhancement

The de Haas-van Alphen effect has been studied in single crystals of purified barium, for magnetic field directions in the (110) plane and in a non-symmetry plane. Three sets of oscillations with minimum frequency values 0.33, 0.46, and 1.95 x 10 3 T have been observed and their angular variations of frequency can be represented by hyperboloidal, ellipsoidal and cylindrical surfaces of revolution about <111>, <111> and <100> respectively. All the oscillations are qualitatively accounted for by associating them with the tetracube hole sheet of the Fermi surface predicted by Johansen’s band structure calculation, but no oscillations arising from the superegg electron sheet have been observed. Cyclotron mass measurements are presented for some extremal orbits and the mass enhancement factor is shown to be small.

scholarly journals Research on GaN MODFET's

1996 ◽  
Vol 1 ◽  
Author(s):  
L. Eastman ◽  
J. Burm ◽  
W. Schaff ◽  
M. Murphy ◽  
K. Chu ◽  
...  
Keyword(s):  
Simple Model ◽  
Quantum Wells ◽  
High Frequency ◽  
Channel Model ◽  
Model Design ◽  
Sapphire Substrates ◽  
Electron Sheet ◽  
Density Values ◽  
Initial Results ◽  
Sheet Density

Initial results on 0.25 μm gate MODFET's have yielded ft=21.4 GHz and fmax=77.5 GHz. These devices have characteristics that agree with the gradual channel model dominated by the electron mobility. The AlGaN/GaN structure, grown on sapphire substrates, are polycrystalline, and thus yield low mobility (<100cm2/Vs) at low electron sheet density. Using a simple model, design optimization predicts electron sheet density values of 7.3 × 1012 cm−2 in thin, 3 nm quantum wells for single-sided doping with 5 nm spacer for use in future high frequency Al0.4Ga0.6N/In0.25Ga0.75N/GaN MODFET's with gate lengths of 0.10 μm. Double sided doping with 5 nm spacers would yield a sheet density of 1.4 × 1013cm−2 in such 3 nm quantum wells.

Electron Sheet Beam Focusing with Tape Ladder Lines

1960 ◽  
Vol 31 (10) ◽  
pp. 1814-1820 ◽  
Author(s):  
William E. Waters
Keyword(s):  
Beam Focusing ◽  
Electron Sheet

Two-dimensional electron gas scattering mechanisms in AlGaN/GaN heterostructures

2000 ◽  
Vol 639 ◽  
Author(s):  
E. Borovitskaya ◽  
W. Knap ◽  
M. S. Shur ◽  
R. Gaska ◽  
E. Frayssinet ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Potential Scattering ◽  
High Electron ◽  
Two Dimensional ◽  
Scattering Mechanisms ◽  
Low Field ◽  
Interface Scattering ◽  
Electron Sheet ◽  
Dimensional Electron Gas ◽  
Experimental And Theoretical Studies

ABSTRACTWe present the results of the experimental and theoretical studies of the low field mobility of two-dimensional electrons in the homoepitaxial AlGaN/GaN heterostructures and in the AlGaN/GaN heterostructures grown on SiC. We show that, at cryogenic temperatures, the temperature dependence of the mobility is primarily determined by the deformation potential scattering and that most of other important scattering mechanisms are temperature independent. We show also that two-dimensional (2D) and three-dimensional (3D) mobility models yield very close results. The analysis of the mobility dependence on the electron sheet density ns shows two possible explanations of the non monotonic mobility versus carrier density dependence: i) the alloy/interface scattering and ii) transfer of the 2D electrons into 3D states in GaN. We present experimental data suggesting that for high 2D gas densities in the investigated structure grown on SiC the 2D-3D transition should take place and might be responsible for the mobility decrease at high electron sheet densities.

Sign in / Sign up

Export Citation Format

Share Document