Anomalous feedback and negative domain wall resistance. (4th October 2016)

• Record Type: Journal Article
• Authors: Cheng, Ran; Zhu, Jian-Gang; Xiao, Di
• Is Part Of: Journal of physics. Volume 49:Number 43(2016)
• Publication Date: 2016-10-04
• Subjects: feedback -- spin-transfer torque -- spin-motive force -- negative resistance -- domain wall dynamics; Physics -- Periodicals; 530
• DOI: 10.1088/0022-3727/49/43/434001
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: 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 β is about twice the value of the Gilbert damping constant α . The anomalous feedback manifests as a negative domain wall resistance, which has an analogy with the water turbine.