  We report observation of a "non-volatile" converse magneto-electric effect in
elliptical FeGa nanomagnets delineated on a piezoelectric PMN-PT substrate. The
nanomagnets are initially magnetized with a magnetic field directed along their
nominal major axis and subsequent application of an electric field across the
substrate generates strain in the substrate, which is partially transferred to
the nanomagnets and rotates the magnetizations of some of them to metastable
orientations. There they remain after the field is removed, resulting in
"non-volatility". In isolated nanomagnets, the angular separation between the
initial and final magnetization directions is < 90 deg, but in a dipole-coupled
pair consisting of one "hard" and one "soft" nanomagnet, the soft nanomagnet's
magnetization is rotated by > 90 deg from the initial orientation because of
the dipole influence of the hard nanomagnet. These effects can be utilized for
ultra-energy-efficient logic and memory devices.
