Measurement of the spin relaxation time of single electrons in a silicon metal-oxide-semiconductor-based quantum dot.

We demonstrate direct detection of individual electron spin states, together with measurement of spin relaxation time (T1), in silicon metal-oxide-semiconductor-based quantum dots (QD). Excited state spectroscopy of the QD has been performed using a charge-sensing technique. T1 of single spin excited states has been done in the time domain by a pump-and-probe method. For an odd and an even number of electrons, we found a magnetic field dependent and invariant T1, respectively.