Spin resonance of electrons confined by SiGe nanostructures

We performed electron spin resonance measurements at 9.56 GHz on SiGe nanostructures to study coherence and relaxation times of electron spins in Si confined by SiGe quantum dots. Multilayers of self-assembled SiGe quantum dots were grown by molecular beam epitaxy. With illumination below the Si bandgap the intensity of the ESR signal increases strongly. We discuss the relationship between structural parameters of the layers and resulting spin coherence and relaxation times of the confined spins as measured by ESR.