1204.0843 (C. H. Yang et al.)

Orbital and valley state spectra of a one-electron silicon quantum dot
probed via charge sensing    [PDF]

C. H. Yang, W. H. Lim, N. S. Lai, A. Morello, A. S. Dzurak

We report a study of the energy spectra of a few-electron silicon metal-oxide-semiconductor quantum dot using dynamic charge sensing and pulsed-voltage spectroscopy with no electron transport through the dot. The occupancy of the quantum dot is probed down to the single electron level using a nearby single-electron transistor as a charge sensor. The first orbital excited state is found to decrease rapidly as the electron occupancy increases from N = 1 to 4. By monitoring the spin filling of the first 4 electrons we extract a valley splitting of ~230 ueV, which is sufficient for the realization of spin qubits in silicon quantum dots.

View original: http://arxiv.org/abs/1204.0843