Abstract
The magnetotransport of highly mobile two-dimensional electrons is studied in GaAs single quantum wells with three occupied subbands. The bottoms of the lower two subbands have nearly the same energy while the bottom of the third subband has a much higher energy (). Magnetointersubband oscillations (MISOs) between the and subbands are observed and obey the relation , where is the cyclotron frequency and is an integer. The slight difference in the energies of the lower subbands produces noticeable interference effects in the magnetoresistance. In contrast to the case of two populated subbands, by analyzing the amplitude of each component of the MISOs separately, the quantum lifetime of electrons in the subband is extracted. The studies show that . The temperature variation of is found to be proportional to , indicating that the electron-electron interaction is the dominant source of the decrease of the electron lifetime at high temperatures. Different temperature dependence of the quantum scattering rate is found in the third subband, , which is consistent with the theory of sparsely populated subbands.
- Received 10 August 2015
DOI:https://doi.org/10.1103/PhysRevB.92.155411
©2015 American Physical Society