Abstract
The electron and nuclear spin properties of nanostructures based on n-CdTe are studied experimentally and theoretically. Spatiotemporal electron spin dynamics in epitaxial n-CdTe are revealed by the newly developed angle-resolved spin noise spectroscopy (AR-SNS), which provides direct access to electron spin fluctuations with wavevectors up to 10 μm−1 via goniometric homodyne detection. Experiments reveal that spin correlations between localized and delocalized electrons have a profound impact on the spin relaxation of localized electrons even at temperatures that are low compared to the binding energy. A theoretical two-state model based on Bloch equations is in quantitative agreement with the entire body of acquired experimental data, where spatiotemporal electron spin noise spectra are measured as functions of temperature and donor density, faithfully reproducing all the experimentally observed spectra.The nuclear spin system of n-CdTe is investigated in two distinctive samples containingwide single quantum wells by a multistage technique combining optical pumping and Hanle effect-based detection, accompanied by theoretical modeling. In the presence of neutral donors, applying weak fields of the order and in excess of the local field leads to the inhibition of nuclear spin diffusion due to the onset of a nuclear spin diffusion barrier, which is shown to be afforded by the combination of strong neutron donor localization, sparse nuclear spin system, and small local field found in CdTe. An opposite picture is observed when the electron structure of the sample is dominated by dilute electron gas puddles, with essentially field-independent nuclear spin relaxation following a Korringa-like relaxation process.