Photon Echoes Produced by Switching Electric Fields

Abstract

We demonstrate photon echoes in Eu${}^{3+}$:Y${}_2$SiO${}_5$ by controlling the inhomogeneous broadening of the Eu${}^{3+}$ ${}^7$F${}_0{\leftrightarrow }^5$D${}_0$ optical transition. This transition has a linear Stark shift and we induce inhomogeneous broadening by applying an external electric field gradient. After optical excitation, reversing the polarity of the field rephases the ensemble, resulting in a photon echo. This is the first demonstration of such a photon echo and its application as a quantum memory is discussed.

improved introduction, including theoretical outline of the relvant quantum memory proposal