EDESR of impurity centers in nanostructures inserted in silicon microcavities

We present the first findings of the new electrically detected electron spin resonance technique (EDESR) which reveal single point defects in the ultra-narrow silicon quantum wells (Si-QW) confined by the superconductor δ-barriers. This technique allows the ESR identification without the application of the external cavity as well as the high frequency (hf) source and recorder, with measuring the only magnetoresistance caused by the hf emission from the δ-barriers in the presence of the microcavity embedded in the Si-QW plane. The new resonant positive magnetoresistance data are interpreted here in terms of the interference transition in the diffusive transport of free holes respectively between the weak antilocalization regime in the range of magnetic fields far from the ESR of a paramagnetic point defect located inside or near the conductive channel and the weak localization regime in the range of magnetic fields corresponding to the ESR of that defect. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)