Control of the polarization flop direction in multiferroic RMnO3 (R = Tb, Dy) by a tilted magnetic field

In spin-driven ferroelectrics, the electric polarization is often modified by the application of a magnetic field. RMnO3 (R = Tb, Dy) is a well known multiferroic with electric polarization along the c-axis induced by the cycloidal ordering of Mn spin moments in the bc plane, which can be explained by the inverse effect of Dzyaloshinski-Moriya interaction. RMnO3 exhibits an electric-polarization flop from P//c to P//a originating from a rotation of the cycloidal plane from the bc to ab plane by a magnetic field applied along the b-axis. Here we show that the polarization flop direction in RMnO3 of +90 or -90 degees can be selected by changing the tilting direction of the applied magnetic field from the b-axis.