THE EFFECTS OF WEAK-LOCALIZATION AND HOLE -HOLE INTERACTION IN BORON DELTA-LAYERS OF EPITAXIAL SILICON

The pioneering measurements of galvanomagnetic properties of a boron d elta-layer of epitaxial silicon (charge carrier concentration being 7. 10(13) cM(-2)) in weak magnetic fields ranged from 10(-3) to 2 T at te mperatures between 1.7 and 50 K we carried out. The temperature depend ence of conductivity was shown to be due to the combined effect of wea k localization (WL) under spin-orbit interaction and hole-hole couplin g (HHC) in the diffusion channel. Based on the data on temperature dep endences of magnetoconductivity and Hall effect, the contributions fro m the WL and HHC effect were separated and their typical parameters we re determined. The magnetic field dependences that are described with a high degree of accuracy by the WL expressions not involving the HHC in the diffusion channel were used to obtain absolute values and tempe rature dependence of phase relaxation time of the electron wave functi on tau(phi) proportional to T-1, indicating the dominant role of hole- hole interactions in inelastic relaxation at low temperatures. Compari son between magnetoresistances in magnetic fields perpendicular and pa rallel to the delta-layer made it possible to evaluate the effective t hickness of the quasi-two-dimensional hole channel which appears to be equal to (8.5 +/- 0.5) . 10(-9) m throughout the whole temperature ra nge studied.