APPLIED PHYSICS: An Electrical Spin on Magnetism

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Science  27 Apr 2007:
Vol. 316, Issue 5824, pp. 517c
DOI: 10.1126/science.316.5824.517c

Magnetic ferroelectrics (multiferroics) are materials that can respond to electric and magnetic fields. It is common in devices such as hard drives to take advantage of the large response (to an applied magnetic field) of the electronic state of a material with giant magnetoresistance. In contrast, the inverse effect, control of the magnetic structure by an applied electric field, is comparatively rare. Because of the prospect of faster switching times in smaller memory devices, there is much interest in developing such electrically controlled magnetic materials.

Recent theoretical work suggested that a key property to look for in such a material is spin chirality: It was proposed that materials in which the magnetic moments of the individual atoms form a spiral structure should also exhibit an electrical response. Yamasaki et al. go some way toward putting that theory into practice by showing that the spin helicity in single crystalline TbMnO3 can be electrically switched from rotating clockwise to counterclockwise by application of an electric poling field as the material is cooled through the helical spin transition temperature. Probing by neutron scattering revealed that the handedness of the chiral spin structure is controlled by the polarity of the poling field. — ISO

Phys. Rev. Lett. 98, 147204 (2007).

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