Coherent manipulation of electron spins up to ambient temperatures in Cr5+(S=1/2) doped K3NbO8

We report coherent spin manipulation on Cr5+ (S=1/2, I=0) doped K3NbO8, which constitutes a dilute two-level model relevant for use as a spin qubit. Rabi oscillations are observed for the first time in a spin system based on transition metal oxides up to room temperature. At liquid helium temperature the phase coherence relaxation time T-2 reaches similar to 10 mu s and, with a Rabi frequency of 20 MHz, yields a single-qubit figure of merit Q(M) of about 500. This shows that a diluted ensemble of Cr5+ (S=1/2) doped K3NbO8 is a potential candidate for solid-state quantum information processing.