WEAK 2D HOLE LOCALIZATION ON THE (0001)TE SURFACE UNDER HYDROSTATIC-PRESSURE

Effect of hydrostatic pressure on the anomalous magnetoresistance (AMR ) of the two-dimensional (2D) hole layer on (0001) surface of Te has b een studied. Application of hydrostatic pressure was found to reverse the sign of AMR of the 2D hole system from positive to negative. The r esults are interpreted in terms of weak localization theory for nonint eracting particles, modified by taking into account the specific featu res of tellurium valence-band energy spectrum, namely, lifted spin deg eneracy, many-valley nature, smd trigonal spectrum distortion on the ( 0001) plane. The pressure dependences of the characteristic relaxation times representing the parameters of the theory have been found. It i s shown that hydrostatic pressure symmetrizes the 2D hole spectrum at the (0001)Te surface, which manifests itself, in particular, in a redu ced trigonal distortion of the spectrum. The pressure dependence of th e spin-orbit splitting between the midpoint of the gap separating the two uppermost valence subbands and the lowest, spin-degenerate subband , Delta(1)(P), has been determined. (C) 1997 American Institute of Phy sics.