Advanced

Electron Scattering Mechanisms in Low-Dimensional Transport Physics

Wang, Qin (1999)
Abstract
Electron scattering mechanisms in low-dimensional semiconductor systems have been investigated at low temperatures.



The influence of scatterers on magnetotransport in a high-mobility, GaAs/AlGaAs two-dimensional electron gas (2DEG) system was studied. A certain number of scattering centres are introduced into the 2DEGs by proton irradiation and can be removed by annealing. The transport properties were compared before and after irradiation and subsequent annealing.



The Coulomb scattering and alloy scattering in modulation-doped GaInAs/InP quantum wells (QWs) have been studied. To modify the Coulomb scattering, the self-assembled InAs quantum dots located just above the QWs were produced by MOVPE. A top... (More)
Electron scattering mechanisms in low-dimensional semiconductor systems have been investigated at low temperatures.



The influence of scatterers on magnetotransport in a high-mobility, GaAs/AlGaAs two-dimensional electron gas (2DEG) system was studied. A certain number of scattering centres are introduced into the 2DEGs by proton irradiation and can be removed by annealing. The transport properties were compared before and after irradiation and subsequent annealing.



The Coulomb scattering and alloy scattering in modulation-doped GaInAs/InP quantum wells (QWs) have been studied. To modify the Coulomb scattering, the self-assembled InAs quantum dots located just above the QWs were produced by MOVPE. A top gate was used to control the charging and decharging of the InAs dots. The experimental results show that the Coulomb field from the trapped electrons is important for inter-channel scattering processes between edge channels formed in magnetic fields. Also, the fractional quantum Hall effect (FQHE) is observed in the GaInAs/InP QWs. To the best of our knowledge, this is the first observation of the FQHE in GaInAs/InP quantum wells.



The fabrication and characterization of regrown GaInAs/InP electron waveguides are presented. In particular, the conductance oscillations induced by the formation of longitudinal resonant electron states in the waveguide are observed and analysed. (Less)
Please use this url to cite or link to this publication:
author
opponent
  • Prof Lindelof, Poul Erik, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
publishing date
type
Thesis
publication status
published
subject
keywords
electron scattering mechanisms, mobility, scattering time, Coulomb scattering, alloy scattering, edge states, quantum Hall effect, SdH, conductance oscillations, quantized conductance, GaInAs/InP, Low-dimensional structures, GaAs/AlGaAs, Physics, Fysik, Fysicumarkivet A:1999:Wang
pages
138 pages
publisher
Solid State Physics, Lund University
defense location
Fysiska institutionens föreläsningssal A
defense date
1999-05-04 10:15
external identifiers
  • Other:LUFTD2(TFFF-0054)1-138
ISBN
91-628-3436-3
language
English
LU publication?
no
id
06cbda7d-0097-40c0-8af9-4774e903d338 (old id 39601)
date added to LUP
2007-10-02 16:01:52
date last changed
2016-09-19 08:45:12
@misc{06cbda7d-0097-40c0-8af9-4774e903d338,
  abstract     = {Electron scattering mechanisms in low-dimensional semiconductor systems have been investigated at low temperatures.<br/><br>
<br/><br>
The influence of scatterers on magnetotransport in a high-mobility, GaAs/AlGaAs two-dimensional electron gas (2DEG) system was studied. A certain number of scattering centres are introduced into the 2DEGs by proton irradiation and can be removed by annealing. The transport properties were compared before and after irradiation and subsequent annealing.<br/><br>
<br/><br>
The Coulomb scattering and alloy scattering in modulation-doped GaInAs/InP quantum wells (QWs) have been studied. To modify the Coulomb scattering, the self-assembled InAs quantum dots located just above the QWs were produced by MOVPE. A top gate was used to control the charging and decharging of the InAs dots. The experimental results show that the Coulomb field from the trapped electrons is important for inter-channel scattering processes between edge channels formed in magnetic fields. Also, the fractional quantum Hall effect (FQHE) is observed in the GaInAs/InP QWs. To the best of our knowledge, this is the first observation of the FQHE in GaInAs/InP quantum wells.<br/><br>
<br/><br>
The fabrication and characterization of regrown GaInAs/InP electron waveguides are presented. In particular, the conductance oscillations induced by the formation of longitudinal resonant electron states in the waveguide are observed and analysed.},
  author       = {Wang, Qin},
  isbn         = {91-628-3436-3},
  keyword      = {electron scattering mechanisms,mobility,scattering time,Coulomb scattering,alloy scattering,edge states,quantum Hall effect,SdH,conductance oscillations,quantized conductance,GaInAs/InP,Low-dimensional structures,GaAs/AlGaAs,Physics,Fysik,Fysicumarkivet A:1999:Wang},
  language     = {eng},
  pages        = {138},
  publisher    = {ARRAY(0x8b2d440)},
  title        = {Electron Scattering Mechanisms in Low-Dimensional Transport Physics},
  year         = {1999},
}