We demonstrate the injection and detection of electrically and thermally generated spin currents probed in Co$_2$MnSi/Cu lateral spin valves. Devices with different electrode separations are patterned to measure the non-local signal as a function of the electrode spacing and we determine a relatively high effective spin polarization $α$ of Co$_2$MnSi to be 0.63 and the spin diffusion length of Cu to be 500 nm at room temperature. The electrically generated non-local signal is measured as a function of temperature and a maximum signal is observed for a temperature of 80 K. The thermally generated non-local signal is measured as a function of current density and temperature in a second harmonic measurement detection scheme. We find different temperature dependences for the electrically and thermally generated non-local signals, which allows us to conclude that the temperature dependence of the signals is not just dominated by the transport in the Cu wire, but that there is a crucial contribution from the different generation mechanisms, which has been largely disregarded to date.
Role of NiO in the nonlocal spin transport through thin NiO films on Y$_3$Fe$_5$O$_{12}$
在自旋输运实验中，自旋电流通过反铁磁（AFM）材料传播，反铁磁被视为一个主要的被动自旋导体不产生或增加任何自旋电流的系统。AFM NiO的自旋电流transmittance受磁场涨落的影响，在Néel温度处达到峰值，并通过降低温度而降低。为了研究原子力显微镜在局域和非局域自旋输运实验中的作用，我们发送自旋电流通过NiO的不同厚度放置在Y $_3$ Fe $_5$ O $_{12}$。自旋电流通过电或热梯度注入，并在很宽的温度和磁场强度范围内进行测量。透射作用反映在局部电注入信号的符号变化和通过降低温度而降低的所有其它信号的信号强度中。然而，热产生的信号显示出低于100 $\,$ K的额外的上升，其不受NiO厚度增加的影响。热导率的变化可能会影响这些信号。的温度和磁场的依赖性是类似的散装NiO，表明NiO本身有助于热诱导的自旋电流。
Spin-Polarized Magnetic Metal Electrodes for Magnetic Tunnel Junctions
School of Materials Science and Engineering, Beihang University（北京航空航天大学材料科学与工程学院）；State Key Laboratory of Tropic Ocean Engineering Materials and Materials Evaluation, Beihang University（热带海洋工程材料与材料评价国家重点实验室，北京航空航天大学）；The Analysis & Testing Center, Beihang University（北京航空航天大学分析测试中心）
Impact of electromagnetic fields and heat on spin transport signals in Y$_{3}$Fe$_{5}$O$_{12}$
探索实现磁振子逻辑的新策略是进一步发展磁振子自旋电子学的关键要求。在这项工作中，我们实现了一个三端磁振子输运装置，研究了通过局域磁场和热产生来操纵磁绝缘体中磁振子自旋信息转移的可能性。该器件包括两个平行的Pt线以及Cu中心线，其沉积在亚铁磁绝缘体Y $_{3}$ Fe $_{5}$ O $_{12}$上。当Pt线用作自旋电流注入器和检测器时，Cu线用于产生局部静磁场和额外的热，其影响下面的Y $_{3}$ Fe $_{5}$ O $_{12}$内的磁结构和磁振子。我们表明，这些因素可以创建一个非本地的信号，显示类似的功能相比，电致磁振子流。此外，观察到的Pt线之间的自旋输运信号的调制，这可以部分地解释由不同的极化热激发的自旋电流。我们的研究结果表明了一种潜在的方式走向操纵的非本地磁振子信号，这可能是有用的磁振子逻辑。
