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We present the findings of spin-dependent single-hole and pair-hole transport revealed by the p-type high mobility silicon quantum wells (Si-QW), 2nm, confined by the superconductor δ-barriers on the n-type Si (100) surface. The oscillations of the conductance in normal state and the zero-resistance supercurrent in superconductor state as a function of the gate voltage are found to be correlated by on- and off-resonance tuning the two-dimensional levels of holes with the Fermi energy in the superconductor barriers. The SIMS and STM studies have shown that the δ-barriers, 3 nm, heavily doped with boron, 5 1021 cm-3, represent really alternating arrays of undoped and doped tetrahedral dots with dimensions restricted to 2 nm. The value of the boron concentration determined by the SIMS method seems to indicate that each doped dot located between undoped dots contains two impurity atoms of boron. The EPR and the thermo-emf studies show that these boron pairs are the trigonal dipole centres, B+-B-, which are caused by the negative-U reconstruction of the shallow boron acceptors, 2B0=>B+-B-. In common with the other solids that consist of small bipolarons, the δ-barriers containing the dipole boron centres have been found to be in an excitonic insulator regime at the density of holes in the Si-QW lower than 1011 cm-2. However, the electrical resistivity, thermo-emf and magnetic susceptibility measurements demonstrate that the high density of holes in the Si-QW (>1011 cm-2) gives rise to the superconductor properties for the δ-barriers in frameworks of the Josephson coupling, the mechanism of which is varied from pair-hole tunneling to the Andreev reflection. Besides, the exchange interaction of the single holes with the dipole boron centres in the δ-barriers is observed to result in their spin polarization revealed by the Andreev reflection as function of the gate voltage. This spin hole polarization appears to give rise to the spin transistor and spin Hall effects in the Si-QW plane as a result of the Rashba SOI. |