The two-dimensional electron gas (2DEG) formed at the interface between SrTiO₃ (STO) and LaAlO₃ (LAO) insulating layer is supposed to possess strong Rashba spin–orbit coupling. To date, the inverse Edelstein effect (i.e., spin-to-charge conversion) in the 2DEG layer is reported. However, the direct effect of charge-to-spin conversion, an essential ingredient for spintronic devices in a current-induced spin–orbit torque scheme, has not been demonstrated yet. Here we show, for the first time, a highly efficient spin generation with the efficiency of ∼6.3 in the STO/LAO/CoFeB structure at room temperature by using spin torque ferromagnetic resonance. In addition, we suggest that the spin transmission through the LAO layer at a high temperature range is attributed to the inelastic tunneling via localized states in the LAO band gap. Our findings may lead to potential applications in the oxide insulator based spintronic devices.

中文翻译：

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SrTiO ₃ -LaAlO ₃氧化物界面处的室温巨型电荷自旋转换

在SrTiO ₃（STO）和LaAlO ₃之间的界面处形成的二维电子气（2DEG）（LAO）绝缘层应该具有强Rashba自旋-轨道耦合。迄今为止，已报道了2DEG层中的逆爱德斯坦效应（即自旋至电荷转换）。但是，尚未证明电荷到自旋转换的直接作用，这是电流感应自旋轨道扭矩方案中自旋电子器件必不可少的组成部分。在这里，我们首次展示了利用自旋扭矩铁磁共振在室温下在STO / LAO / CoFeB结构中具有〜6.3效率的高效自旋产生。另外，我们建议在高温范围内通过LAO层的自旋传输归因于LAO带隙中局部状态的非弹性隧穿。我们的发现可能会导致在基于氧化物绝缘子的自旋电子器件中的潜在应用。