標題: Cyclotron masses and g-factors of hybridized electron-hole states in InAs/GaSb quantum wells
作者: Nilsson, K.
Zakharova, A.
Lapushkin, I.
Yen, S. T.
Chao, K. A.
電子工程學系及電子研究所
Department of Electronics Engineering and Institute of Electronics
公開日期: 1-Aug-2006
摘要: Using the eight-band k center dot p model and the Burt-Foreman envelope function theory to perform self-consistent calculations, we have studied the effect of electron-hole hybridization on the cyclotron masses m(*) and the effective g-factors g(*) of two-dimensional quasiparticles in InAs/GaSb quantum wells under a magnetic field applied perpendicular to the interfaces. We can modify the degree of hybridization by changing the InAs and/or GaSb layer width, or by inserting a thin AlSb barrier. While electron-light-hole hybridization dominates at both low and high fields, due to a sequence of anticrossings between electronlike and heavy-holelike levels, there is also an important contribution from heavy-hole states to the strong hybridization in the intermediate field range. The field-dependence of the hybridized energy eigenstates is manifested in the variations of m(*) and g(*). Characteristic discontinuous changes of both m(*) and g(*) appear at each anticrossing, resulting in a magnetic-field-driven oscillating behavior of these quantities for electronlike states of a given Landau level index. The electron g-factor can change sign when two eigenstates anticross. Hybridization of electron and hole states enhances the electron effective mass, and we have found a complicated dependence of this effect on the interaction strength. Without inserting an AlSb barrier, the strong interaction between the electronlike and the light-holelike states at low magnetic fields produces a large level repulsion, and hence relatively small effective masses and g-factors associated with these states. Intermediate interaction leads to weaker level repulsion and therefore very heavy electron cyclotron masses as well as large g-factors associated with the lowest Landau levels. A weak interaction only enhances the cyclotron masses of the electronlike states slightly. The hole effective masses change with both the magnetic field and the sample structure in a more complicated fashion.
URI: http://dx.doi.org/10.1103/PhysRevB.74.075308
http://hdl.handle.net/11536/11986
ISSN: 1098-0121
DOI: 10.1103/PhysRevB.74.075308
期刊: PHYSICAL REVIEW B
Volume: 74
Issue: 7
起始頁: 0
結束頁: 0
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