Quantum effects in hole-type Si/SiGe heterojunctions

Abstract

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 quantum interference effects — weak localization of the mobile charge carriers, and 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: τφ=6.6×10−12T−1 s. This dependence τφ∝T−1 must be regarded as a manifestation of hole–hole scattering processes in the two-dimensional electron system. The contribution to the magnetoresistance from the hole–hole interaction in the Cooper channel is extracted, and the corresponding interaction constant λ0C≈0.5 is found.