Coherent spin dynamics of ytterbium ions in yttrium orthosilicate

We investigate the electron and nuclear spin coherence properties of ytterbium (Yb3+) ions with nonzero nuclear spin, within an yttrium orthosilicate (Y2SiO5) crystal, with a view to their potential application in quantum memories or repeaters. We find electron spin-lattice relaxation times are maximized at low magnetic field (<100 mT), where g similar to 6, reaching 5 s at 2.5 K, while coherence times are maximized when addressing ESR transitions at higher fields where g similar to 0.7, where a Hahn echo measurement yields T-2 up to 73 mu s. Dynamical decoupling can be used to suppress spectral diffusion and extend the coherence lifetime to over 0.5 ms, close to the limit of instantaneous diffusion. Using Davies electron-nuclear double resonance, we performed coherent control of the Yb-173(3+) nuclear spin and studied its relaxation dynamics. At around 4.5 K we measure nuclear spins T-1 and T-2 of 4 and 0.35 ms, respectively, about 4 and 14 times longer than the corresponding times for the electron spin.