  We have experimentally investigated the hole states in a gated vertical
strained Si/SiGe quantum dot. We demonstrate the inhomogeneous strain
relaxation on the lateral surface creates a ring-like potential near the
perimeter of the dot, which can confine hole states exhibiting quantum ring
characteristics. The magnetotunneling spectroscopy exhibits the predicted
periodicity of energy states in \phi/\phi0, but the magnitude of the energy
shifts is larger than predicted by simple ring theory. Our results suggest a
new way to fabricate and study quantum ring structures.
