Quantum and Transport Mobilities of Electrons in GaAs/Ga1xAlxAs Multiple Quantum Wells

Abstract

The quantum and transport mobilities of electrons in modulation-doped GaAs/Ga 1±x Al x As multiple quantum wells with well widths in the range between 51 and 145 A Ê and carrier density of about 1Â10 16 m ±2 have been investigated by magnetotransport measurements. The magnetic field dependence of the amplitude of the quantum oscillations in both magnetoresistance and Hall resistance have been used to determine the quantum (t q ) and transport (t t ) lifetimes (and hence the quantum (m q ) and transport (m t ) mobilities) of 2D electrons. The values thus found for m t are substantially smaller than those of the Hall mobility (m H ) as obtained in the ohmic regime at low magnetic fields. The discrepancy between m t and m H has been explained in terms of a transport lifetime t t that depends on the electron energy due to the scattering of electrons by interface roughness in the quantum wells.

Energy Relaxation Rates in AlInN/AlN/GaN Heterostructures

“…3,25,26,43,44 The SdH oscillations have also been obtained by subtracting the background magnetoresistance (in the form of a polynomial of second degree) from the raw experimental data (DR ¼ R xx À R b ). 45 The values obtained for effective mass and quantum lifetime from the temperature and magnetic field dependence of the normalized amplitude of the oscillations in…”