Anomalous feedback and negative domain wall resistance

作者：Cheng Ran^*; Zhu Jian Gang; Xiao Di

来源：Journal of Physics D: Applied Physics , 2016, 49(43): 434001.

DOI：10.1088/0022-3727/49/43/434001

• feedback
• spin-transfer torque
• spin-motive force
• negative resistance
• domain wall dynamics

Magnetic induction can be regarded as a negative feedback effect, where the motive-force opposes the change of magnetic flux that generates the motive-force. In artificial electromagnetics emerging from spintronics, however, this is not necessarily the case. By studying the current-induced domain wall dynamics in a cylindrical nanowire, we show that the spin motive-force exerting on electrons can either oppose or support the applied current that drives the domain wall. The switching into the anomalous feedback regime occurs when the strength of the dissipative torque beta is about twice the value of the Gilbert damping constant alpha. The anomalous feedback manifests as a negative domain wall resistance, which has an analogy with the water turbine.

• 出版日期2016-11-2