Qiu Zhiyong, Hou Dazhi, Barker Joseph, Yamamoto Kei, Gomonay Olena, Saitoh Eiji
Institute for Materials Research, Tohoku University, Sendai, Japan.
Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams (Ministry of Education), School of Materials Science and Engineering, Dalian University of Technology, Dalian, China.
Nat Mater. 2018 Jul;17(7):577-580. doi: 10.1038/s41563-018-0087-4. Epub 2018 May 28.
Colossal magnetoresistance (CMR) refers to a large change in electrical conductivity induced by a magnetic field in the vicinity of a metal-insulator transition and has inspired extensive studies for decades. Here we demonstrate an analogous spin effect near the Néel temperature, T = 296 K, of the antiferromagnetic insulator CrO. Using a yttrium iron garnet YIG/CrO/Pt trilayer, we injected a spin current from the YIG into the CrO layer and collected, via the inverse spin Hall effect, the spin signal transmitted into the heavy metal Pt. We observed a two orders of magnitude difference in the transmitted spin current within 14 K of the Néel temperature. This transition between spin conducting and non-conducting states was also modulated by a magnetic field in isothermal conditions. This effect, which we term spin colossal magnetoresistance (SCMR), has the potential to simplify the design of fundamental spintronics components, for instance, by enabling the realization of spin-current switches or spin-current-based memories.
巨磁电阻（CMR）是指在金属-绝缘体转变附近由磁场引起的电导率的大幅变化，几十年来一直激发着广泛的研究。在此，我们展示了在反铁磁绝缘体CrO的奈尔温度T = 296K附近的一种类似的自旋效应。使用钇铁石榴石YIG/CrO/Pt三层结构，我们将自旋电流从YIG注入到CrO层，并通过逆自旋霍尔效应收集传输到重金属Pt中的自旋信号。我们在奈尔温度的14K范围内观察到传输的自旋电流有两个数量级的差异。这种自旋传导和非传导状态之间的转变在等温条件下也受到磁场的调制。我们将这种效应称为自旋巨磁电阻（SCMR），它有可能简化基本自旋电子学元件的设计，例如，通过实现自旋电流开关或基于自旋电流的存储器。
