Parabolic negative magnetoresistance in p-Ge/Ge1-xSix heterostructures

Quantum corrections for the conductivity due to the weak localization (WL) and the disorder-modified electron-electron interaction (EEI) are investiga ted for the high-mobility multilayer p-Ge/Ge1-xSex heterostructures at T=(0 .1-20) K in magnetic field B up to 1.5 T. Negative magnetoresistance with l ogarithmic dependence on T and linear in B-2 is observed for B greater than or equal to 0.1 T. Such a behavior is attributed to the connection between the classical cyclotron motion and the EEI effect. The Hartree part of the interaction constant is estimated (F-sigma=0.44) and the WL and EEI contri butions to the total quantum correction Delta sigma at B=0 are separated (D elta sigma(WL)approximate to 0.3 Delta sigma; Delta sigma(ee)approximate to 0.7 Delta sigma). (C) 1999 American Institute of Physics. [S1063-7826(99)0 1209-0].