Spin colossal magnetoresistance in an antiferromagnetic insulator
Spin colossal magnetoresistance in an antiferromagnetic insulator
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DOI：
10.1038/s41563-018-0087-4
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发表时间：
2018-07-01
期刊：
影响因子：
41.2
通讯作者：
Saitoh, Eiji
中科院分区：
文献类型：
--
作者：
Qiu, Zhiyong;Hou, Dazhi;Saitoh, Eiji
巨磁阻（CMR）是指在金属-绝缘体转变附近由磁场引起的电导率的大变化，并且几十年来激发了广泛的研究（1，2）。在这里，我们证明了一个类似的自旋效应附近的尼尔温度，TN = 296 K，反铁磁绝缘体Cr2 O3。利用钇铁石榴石YIG/Cr_2O_3/Pt三层膜，我们从YIG向Cr_2O_3层注入自旋电流，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。我们观察到的两个数量级的差异，在14 K内的尼尔温度的传输自旋电流。这种自旋导电和非导电状态之间的转变也调制的磁场在等温条件下。这种效应，我们称之为自旋巨磁阻（SCMR），有可能简化基本自旋电子学组件的设计，例如，通过实现自旋电流开关或基于自旋电流的存储器。
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 Neel 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 14K of the Neel 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 spincurrent-based memories.