报告时间：2017年4月6日上午10：00

报告地点：近代物理系210会议室

报告人：北京航空航天大学电子信息工程学院雷娜副教授

报告题目：“Abnormal spin Hall magnetoresistance in ultra-thin Pt/LSMO”

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摘要：Spin Hall magnetoresistance (SMR) in a non-ferromagnetic/ferromagnetic (NM/FM) bilayer is an angular dependence of resistance of the NM layer on the magnetization of FM layer [1]. It provides an easy approach to explore the spin Hall effect in a simple bilayer system, however several similar effects might be mixed in the system and might complicate the data analysis and interpretation. Here we present a case of ultra-thin Pt/LSMO, in which LSMO (bellow 7 unit cells) layer is an insulating magnetic oxide with Curie temperature of 120K. Below 120K, our results clearly show the coexistence of the anisotropic magnetoresistance (AMR) and SMR effects. However, far above its Curie temperature, where the LSMO is paramagnetic, the magnetoresistance doesn't disappear but even more pronounce, which is distinct from the case of Pt/YIG [2]. Here it is neither SMR nor AMR, and an additional mechanism is required. Anomalous Hall effect was also performed, which is consistent with SMR measurement. We propose some physical pictures which could attribute to this magnetoresistance in paramagnetic state.

[1] H. Nakayama, M. Althammer, Y.-T. Chen, K. Uchida, et al., Phys. Rev. Lett. 110(20), 206601 (2013).

[2] K. Uchida, Z. Qiu, T. Kikkawa, R. Iguchi, E. Saitoh, Appl. Phys. Lett. 106, 052405 (2015)