Giant Charge-to-Spin Conversion Efficiency in SrTiO3 -Based Electron Gas Interface

Abstract

Converting charge to spin in the two-dimensional electron gas (2DEG) at an interface of oxides has shown promise for electrical manipulation of a ferromagnet's magnetization via spin-orbit torque. However, the only efficient system so far is SrTiO${}_{3}$/LaAlO${}_{3}$, the making of which requires complex pulsed laser ablation and intricate pressure and temperature regulation. This work shows that good conversion can also be realized in Ar${}^{+}$-etched SrTiO${}_{3}$ 2DEGs simply fabricated by magnetron sputtering, with about 90% efficiency at room temperature for an etched SrTiO${}_{3}$/Ni-Fe structure---an efficient, easily achieved spin source for spin-orbit-torque applications.