Ferromagnets are commonly magnetized by either external magnetic fields or spin polarized currents. The manipulation of magnetization by spin-current occurs through the spin-transfer-torque effect, which is applied, for example, in modern magnetoresistive random access memory. However, the current density required for the spin-transfer torque is of the order of 1 × 106 A·cm-2, or about 1 × 1025 electrons s-1 cm-2. This relatively high current density significantly affects the devices' structure and performance. Here we demonstrate magnetization switching of ferromagnetic thin layers that is induced solely by adsorption of chiral molecules. In this case, about 1013 electrons per cm2 are sufficient to induce magnetization reversal. The direction of the magnetization depends on the handedness of the adsorbed chiral molecules. Local magnetization switching is achieved by adsorbing a chiral self-assembled molecular monolayer on a gold-coated ferromagnetic layer with perpendicular magnetic anisotropy. These results present a simple low-power magnetization mechanism when operating at ambient conditions.
Bibliographical noteFunding Information:
Y.P. acknowledges support from the Volkswagen Foundation (VW 88 367), from the Israel Science Foundation (ISF grant no. 1248/10), and the MOS Israel. R.N. acknowledges support in part from the European Research Council under the European Union's Seventh Framework Program (FP7/2007-2013)/ERC grant agreement no (338720), from the MOS Israel and from the VW Foundation (VW 88 367). O.B.D. would also like to acknowledge the Israeli Ministry of Science, Technology and Space grant 0399174. Y.P. and O.B.D. thank I. Eisenberg for his helpful and professional graphical contribution to this paper.
© 2017 The Author(s).