Spin filling of valley-orbit states in a silicon quantum dot

W. H. Lim, C. H. Yang, F. A. Zwanenburg, A. S. Dzurak

Published 2011-03-15, updated 2011-07-08Version 2

We report the demonstration of a low-disorder silicon metal-oxide-semiconductor (Si MOS) quantum dot containing a tunable number of electrons from zero to N=27. The observed evolution of addition energies with parallel magnetic field reveals the spin filling of electrons into valley-orbit states. We find a splitting of 0.10 meV between the ground and first excited states, consistent with theory and placing a lower bound on the valley splitting. Our results provide optimism for the realization in the near future of spin qubits based on silicon quantum dots.