Spin-dependent single-hole tunneling in self-assembled silicon quantum rings

We study the quantum conductance revealed by the quantum wire embedded within one of the arms of the Aharonov-Bohm (AB) ring that exhibits a weak localisation regime. The AB ring is prepared inside self-assembled silicon quantum well of the p-type between 6-barriers on the n-type Si(1 0 0) surface. The coherence of the single-hole transport and negative magnetic resistance effect is demonstrated. The positive/negative transformation of the magnetoresistance is found by the electrically detected NMR of the Si-29 nuclei in the weakest magnetic fields, which seems to be caused by the effect of the nuclear spin polarisation on a weak antilocalisation. (C) 2002 Elsevier Science B.V. All rights reserved.