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 been studied. Application of hydrostatic pressure was found to reverse the sign of AMR of the 2D hole system from positive to negative. The results are interpreted in terms of weak localization theory for noninteracting particles, modified by taking into account the specific features of tellurium valence-band energy spectrum, namely, lifted spin degeneracy, many-valley nature, and 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 is shown that hydrostatic pressure symmetrizes the 2D hole spectrum at the (0001)Te surface, which manifests itself, in particular, in a reduced trigonal distortion of the spectrum. The pressure dependence of the spin-orbit splitting between the midpoint of the gap separating the two uppermost valence subbands and the lowest, spin-degenerate subband, Δ₁(P), has been determined. Fiz. Tverd. Tela (St. Petersburg) 39, 568–572 (March 1997)