Magnetic ferroelectrics or multiferroics, which are currently extensively
explored, may provide a good arena to realize a novel magnetoelectric function.
Here we demonstrate the genuine electric control of the spiral magnetic
structure in one of such magnetic ferroelectrics, TbMnO3. A spin-polarized
neutron scattering experiment clearly shows that the spin helicity, clockwise
or counter-clockwise, is controlled by the direction of spontaneous
polarization and hence by the polarity of the small cooling electric field.Comment: 4 pages, 3 figure