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^1,2. Here we demonstrate an analogous spin effect near the Néel temperature, T_N = 296 K, of the antiferromagnetic insulator Cr₂O₃. Using a yttrium iron garnet YIG/Cr₂O₃/Pt trilayer, we injected a spin current from the YIG into the Cr₂O₃ 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.

巨磁致电阻（CMR）指的是金属-绝缘体过渡附近的磁场所引起的电导率的大变化，并激发了数十年来的广泛研究^1,2。在这里，我们 在反铁磁绝缘子Cr ₂ O ₃的Néel温度T _N = 296 K附近表现出类似的自旋效应。使用钇铁石榴石YIG / Cr ₂ O ₃ / Pt三层，将来自YIG的自旋电流注入Cr ₂ O _3中并通过逆自旋霍尔效应收集自旋信号，该自旋信号传输到重金属Pt中。我们在Néel温度的14 K范围内观察到传输的自旋电流有两个数量级的差异。在等温条件下，磁场也调节了自旋传导状态和非传导状态之间的过渡。这种效应，我们称之为自旋巨大磁阻（SCMR），具有潜力，例如，通过实现自旋电流开关或基于自旋电流的存储器，可以简化基本自旋电子器件的设计。