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∼6, reaching 5 s at 2.5 K, while coherence times are maximized when addressing ESR transitions at higher fields where g∼0.7, where a Hahn echo measurement yields T2 up to 73 μs. 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 Yb3+173 nuclear spin and studied its relaxation dynamics. At around 4.5 K we measure nuclear spins T1 and T2 of 4 and 0.35 ms, respectively, about 4 and 14 times longer than the corresponding times for the electron spin.