  The nitrogen-vacancy defect center (NV center) is a promising candidate for
quantum information processing due to the possibility of coherent manipulation
of individual spins in the absence of the cryogenic requirement. We report a
room-temperature implementation of the Deutsch-Jozsa algorithm by encoding both
a qubit and an auxiliary state in the electron spin of a single NV center. By
thus exploiting the specific S=1 character of the spin system, we demonstrate
how even scarce quantum resources can be used for test-bed experiments on the
way towards a large-scale quantum computing architecture.
