Quantum effects in hole-type Si/SiGe heterojunctions

The temperature and magnetic-field dependences of the resistance of Si/SiGe heterojunctions with hole-type conductivity are investigated. It is shown that the features of these dependences are due to a manifestation of quantu m interference effects - weak localization of the mobile charge carriers, a nd the hole-hole interaction in the two-dimensional electron system. On the basis of an analysis of the quantum interference effects, the temperature dependence of the dephasing time of the wave function of the charge carrier is determined: tau(Phi)=6.6x10(-12)T(-1) s. This dependence tau(Phi)propor tional to T-1 must be regarded as a manifestation of hole-hole scattering p rocesses in the two-dimensional electron system. The contribution to the ma gnetoresistance from the hole-hole interaction in the Cooper channel is ext racted, and the corresponding interaction constant lambda(0)(C)approximate to 0.5 is found. (C) 2000 American Institute of Physics. [S1063-777X(00)012 08-1].