Quantum lifetime in the 2DEG from high magnetic field magnetoresistance measurements

We measured the diagonal component of the transverse magnetoresistance in t wo pseudomorphic InxGa1-xAs HEMT structures. The quantum lifetime is obtain ed from the variation of the amplitude of the Shubnikov-de Hass oscillation s with the magnetic field, from Landau levels index between 22 and 5, using a modified Dingle plot method which takes into account the quadratic relat ion between the magnetoresistance and the density of states at the Fermi le vel. The quantum lifetimes found in this manner are consistent with quantum lifetimes determined at low magnetic field using Dingle plots and at high magnetic field with a peak magnetoresistance calculation. (C) 1998 Elsevier Science Ltd. All rights reserved.