Investigation of the spin properties of electrons in zero-dimensional SiGe structures by electron paramagnetic resonance

We present an investigation of the g-factor and the spin coherence time of electrons confined in regular SiGe quantum dot arrays deposited on prepatterned Si substrates. These structures were investigated by photoluminescence and electron paramagnetic resonance both in continuous wave and pulsed mode. The dot structures consist of regular arrays of about 10^10 SiGe quantum dots on a Si(1 0 0) substrate that was prepatterned by e-beam lithography or holographic lithography. These quantum dot systems show an EPR line with a g-factor of conduction electrons in Si. The spin lifetime fits to that of two-dimensional SiGe structures, but the EPR line width shows inhomogeneous broadening. A 2D anisotropy is no longer visible.