EFFECTIVE-MASS OF 2-DIMENSIONAL ELECTRON-GAS IN DELTA-DOPED AL0.48IN0.52AS GA0.47IN0.53AS QUANTUM-WELLS/

We have studied the lowest two subbands of two-dimensional electron ga s in delta-doped AIInAs/GaInAs quantum wells by Shubnikov-de Haas, qua ntum Hall effect, and cyclotron resonance measurements. The effective masses determined by the field-dependent cyclotron resonance measureme nts are 0.0576m(0) and 0.0483m(0) at electron densities of 17.3 and 3. 6X10(11) cm(-2) for the first and second subbands, respectively. It wa s found that the electron in the first subband has heavier effective m ass and shorter quantum lifetime than that in the second subband, Usin g the band gap of 810 meV and the band-edge mass of 0.042m(0) for Ga0. 47In0.53As, we calculated the average distance of the two subbands fro m the conduction band edge to be 150 and 61 meV, respectively. (C) 199 6 American Institute of Physics.