Magnetic domain-wall motion twisted by nanoscale probe-induced spin transfer

Abstract

A method for deterministic control of magnetism using an electrical stimulus is highly desired for the new generation of magnetoelectronic devices. Much effort has been focused on magnetic domain-wall (DW) motion manipulated by a successive injection of spin-polarized current into a magnetic nanostructure. However, an integrant high-threshold current density of ${10}^{11}\ensuremath{\sim}{10}^{12}\phantom{\rule{0.16em}{0ex}}\mathrm{A}/{\mathrm{m}}^{2}$ inhibits the integration with low-energy-cost technology. Here, we report an approach to manipulate a single magnetic domain wall with a perpendicular anisotropy in a manganite/dielectric/metal capacitor using a probe-induced spin displacement. A spin-transfer torque (STT) occurs in the strongly correlated manganite film during the spin injection into the capacitor from the nanoscale magnetized tip with an ultralow voltage of 0.1 V, where a lower bound of the estimated threshold spin-polarized current density is $\ensuremath{\sim}{10}^{8}\phantom{\rule{0.16em}{0ex}}\mathrm{A}/{\mathrm{m}}^{2}$ at the tip/manganite interface. The dynamic of DW motions are analyzed using the Landau-Lifshitz-Gilbert method. This probe-voltage-controlled DW motion, at an ambient condition, demonstrates a critical framework for the fundamental understanding of the manipulation of the nanomagnet systems with low-energy consumption.