Optical measurement of the effect of electric fields on the nuclear spin coherence of rare-earth ions in solids.

We show that the coherence properties of the nuclear spin states of rare-earth ions in solids can be manipulated by small applied electric fields. This was done by measuring the Stark effect on the nuclear quadrupole transitions of (151)Eu in Y(2)SiO(5) (YSO) using a combination of Raman heterodyne optical detection and Stark modulated quadrupole echoes to achieve high sensitivity. The measured Stark coefficients were 0.42 and 1.0 Hz cm/V for the two quadrupole transitions at 34.54 and 46.20 MHz, respectively. The long decoherence time of the nuclear spin states (25 ms) allowed us to make the measurements in very low electric fields of ∼ 10 V/cm, which produced 100% modulation of the nuclear spin echo, and to measure Stark shifts of ∼ 1 Hz or 20 ppm of the inhomogeneous linewidth.