Fig. 2
From: All-optical control of long-lived nuclear spins in rare-earth doped nanoparticles
151Eu3+ spin inhomogeneous and homogeneous linewidths. a Inhomogeneous linewidth of the \(\pm \left| {1{\mathrm{/}}2}\rangle \right. \leftrightarrow \pm \left| {3{\mathrm{/}}2}\rangle \right.\) spin transition obtained by monitoring the spin-echo amplitude as a function of the frequency detuning ω2–ω1 for a fixed time delay 2τ of 400 µs (circles). Solid line: Lorentzian fit corresponding to a full width at half maximum of 107 ± 8 kHz. b Spin-echo decay at zero magnetic field. A single-exponential fit yields a coherence lifetime T2 of 1.3 ± 0.2 ms, corresponding to a Γh = 250 Hz homogeneous linewidth. c Homogeneous linewidth evolution under an applied external magnetic field. A fast decrease in Γh is observed for weak fields, corresponding to a coherence lifetime increasing from 1.3 ms to 2.9 ms (Supplementary Fig. 6). Solid line: modelling by interactions with defects carrying electron spins at a concentration of 6.4 ×1017 cm−3 (see Supplementary Discussion). Error bars and uncertainties correspond to ±1 standard error
