Spin-orbit torques for current parallel and perpendicular to a domain wall
Spin-orbit torques for current parallel and perpendicular to a domain wall
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DOI：
10.1063/1.4931429
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发表时间：
2015-07
影响因子：
4
通讯作者：
T. Schulz;Ó. Alejos;E. Martínez;K. Hals;K. Garcı́a;Kyujoon Lee;R. Conte;G. V. Karnad;S. Moretti;B. Ocker;D. Ravelosona;A. Brataas;M. Klaui
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作者：
T. Schulz;Ó. Alejos;E. Martínez;K. Hals;K. Garcı́a;Kyujoon Lee;R. Conte;G. V. Karnad;S. Moretti;B. Ocker;D. Ravelosona;A. Brataas;M. Klaui
我们报告了场和电流诱导的畴壁（DW）脱钉实验在Ta\Co20Fe60B20\MgO纳米线通过霍尔交叉几何。虽然纯场诱导的脱钉没有显示出对面内场的角度依赖性，但电流的影响主要取决于内部DW结构，我们通过外部磁面内场来操纵该结构。我们示出了平行于DW发送的电流的脱钉测量，并将其脱钉效率与垂直于DW流动的电流的常规情况进行比较。我们发现，最大效率是类似的误差条内的电流方向，这是符合一个占主导地位的阻尼类自旋轨道扭矩（SOT），并表明没有大的额外的扭矩产生的电流垂直于DW。最后，我们发现了不同的依赖性的最大脱钉效率角为不同的DW和钉扎水平。这强调了我们的全角度扫描的重要性，与以前使用的测量相比，只有两个磁场方向（平行和垂直于DW），以确定真实的扭矩强度，并显示了精确的DW结构和钉扎部位的SOT的灵敏度。
We report field- and current-induced domain wall (DW) depinning experiments in Ta\Co20Fe60B20\MgO nanowires through a Hall cross geometry. While purely field-induced depinning shows no angular dependence on in-plane fields, the effect of the current depends crucially on the internal DW structure, which we manipulate by an external magnetic in-plane field. We show depinning measurements for a current sent parallel to the DW and compare its depinning efficiency with the conventional case of current flowing perpendicularly to the DW. We find that the maximum efficiency is similar for both current directions within the error bars, which is in line with a dominating damping-like spin-orbit torque (SOT) and indicates that no large additional torques arise for currents perpendicular to the DW. Finally, we find a varying dependence of the maximum depinning efficiency angle for different DWs and pinning levels. This emphasizes the importance of our full angular scans compared with previously used measurements for just two field directions (parallel and perpendicular to the DW) to determine the real torque strength and shows the sensitivity of the SOT to the precise DW structure and pinning sites.