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Landau level structures and semimetal-semiconductor transition in strained InAs/GaSb quantum wells

Zakharova, A; Yen, ST and Chao, Koung-An LU (2004) In Physical Review B (Condensed Matter and Materials Physics) 69(11).
Abstract
Using Burt's envelope function theory and the scattering matrix method, we investigate the hybridized electron-hole Landau levels in strained InAs/GaSb quantum wells sandwiched between wide-gap AlSb barrier layers under electric and a quantizing magnetic fields applied perpendicular to interfaces. At zero magnetic field, in the structures studied here, the lowest electron level in the InAs layer lies below the highest heavy-hole level in the GaSb layer. With increasing magnetic field, the electron levels move up and the heavy-hole levels move down, producing anticrossings and gaps in the Landau level structures. We have found that the Landau level structures depend strongly on the lattice-mismatched strain and the applied voltage. As a... (More)
Using Burt's envelope function theory and the scattering matrix method, we investigate the hybridized electron-hole Landau levels in strained InAs/GaSb quantum wells sandwiched between wide-gap AlSb barrier layers under electric and a quantizing magnetic fields applied perpendicular to interfaces. At zero magnetic field, in the structures studied here, the lowest electron level in the InAs layer lies below the highest heavy-hole level in the GaSb layer. With increasing magnetic field, the electron levels move up and the heavy-hole levels move down, producing anticrossings and gaps in the Landau level structures. We have found that the Landau level structures depend strongly on the lattice-mismatched strain and the applied voltage. As a result, in the region before anticrossings, the g factor of the lowest electron Landau level has a larger value for the quantum well structure grown on GaSb than that for the structure grown on InAs, while in the region after anticrossings the situation reverses for the g factor. Under low magnetic field, the difference between the electron g factors for the structures grown on different substrates is found to be as large as 10 for zero bias and decreases significantly with increasing bias. When all electron levels become higher than hole levels at high magnetic fields, the semimetal-semiconductor transition occurs. The critical magnetic field B-c for the phase transition in structures grown on InAs is found to be lower than that in structures grown on GaSb. It is also obtained that a positive voltage biased across the InAs/GaSb well essentially decreases B-c. Therefore, for a fixed magnetic field, the semimetal-semiconductor transition can be controlled by a bias. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review B (Condensed Matter and Materials Physics)
volume
69
issue
11
publisher
American Physical Society
external identifiers
  • wos:000220814000093
  • scopus:2142760139
ISSN
1098-0121
DOI
10.1103/PhysRevB.69.115319
language
English
LU publication?
yes
id
ca026e3f-0b4f-4cf3-89d6-d1a660028a6d (old id 905674)
date added to LUP
2008-01-21 10:06:42
date last changed
2017-03-26 04:12:59
@article{ca026e3f-0b4f-4cf3-89d6-d1a660028a6d,
  abstract     = {Using Burt's envelope function theory and the scattering matrix method, we investigate the hybridized electron-hole Landau levels in strained InAs/GaSb quantum wells sandwiched between wide-gap AlSb barrier layers under electric and a quantizing magnetic fields applied perpendicular to interfaces. At zero magnetic field, in the structures studied here, the lowest electron level in the InAs layer lies below the highest heavy-hole level in the GaSb layer. With increasing magnetic field, the electron levels move up and the heavy-hole levels move down, producing anticrossings and gaps in the Landau level structures. We have found that the Landau level structures depend strongly on the lattice-mismatched strain and the applied voltage. As a result, in the region before anticrossings, the g factor of the lowest electron Landau level has a larger value for the quantum well structure grown on GaSb than that for the structure grown on InAs, while in the region after anticrossings the situation reverses for the g factor. Under low magnetic field, the difference between the electron g factors for the structures grown on different substrates is found to be as large as 10 for zero bias and decreases significantly with increasing bias. When all electron levels become higher than hole levels at high magnetic fields, the semimetal-semiconductor transition occurs. The critical magnetic field B-c for the phase transition in structures grown on InAs is found to be lower than that in structures grown on GaSb. It is also obtained that a positive voltage biased across the InAs/GaSb well essentially decreases B-c. Therefore, for a fixed magnetic field, the semimetal-semiconductor transition can be controlled by a bias.},
  author       = {Zakharova, A and Yen, ST and Chao, Koung-An},
  issn         = {1098-0121},
  language     = {eng},
  number       = {11},
  publisher    = {American Physical Society},
  series       = {Physical Review B (Condensed Matter and Materials Physics)},
  title        = {Landau level structures and semimetal-semiconductor transition in strained InAs/GaSb quantum wells},
  url          = {http://dx.doi.org/10.1103/PhysRevB.69.115319},
  volume       = {69},
  year         = {2004},
}