We report the observation of the spin Hall magnetoresistance (SMR) in a paramagnetic insulator. By measuring the transverse resistance in a $\mathrm{Pt}/{\mathrm{Gd}}_3{\mathrm{Ga}}_5{\mathrm{O}}_{12}$ (GGG) system at low temperatures, paramagnetic SMR is found to appear with an intensity that increases with the magnetic field aligning GGG's spins. The observed effect is well supported by a microscopic SMR theory, which provides the parameters governing the spin transport at the interface. Our findings clarify the mechanism of spin exchange at a Pt/GGG interface, and demonstrate tunable spin-transfer torque through the field-induced magnetization of GGG. In this regard, paramagnetic insulators offer a key property for future spintronic devices.

中文翻译：

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顺磁自旋霍尔磁阻

我们报告了顺磁绝缘体中自旋霍尔磁阻 (SMR) 的观察结果。通过测量横向电阻$铂/{钆}_3{嘎}_5{\mathrm{哦}}_{12}$(GGG) 系统在低温下，发现顺磁 SMR 出现的强度随着磁场对齐 GGG 的自旋而增加。观察到的效应得到了微观 SMR 理论的充分支持，该理论提供了控制界面自旋输运的参数。我们的研究结果阐明了 Pt/GGG 界面处的自旋交换机制，并通过 GGG 的场致磁化证明了可调谐的自旋转移扭矩。在这方面，顺磁绝缘体为未来的自旋电子器件提供了关键特性。