Effect of demagnetization factors on spin current transport

Po-Hsun Wu^1*, Ying-Ting Chan², Tzu-Chao Hung², Yi-Hui Zhang^1,2, Danru Qu², Tien-Ming Chuang², C. L. Chien^1,3, Ssu-Yen Huang¹

¹Physics, National Taiwan University, Taipei, Taiwan
²Physics, Academia Sinica, Taipei, Taiwan
³Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland, USA

* Presenter:Po-Hsun Wu, email:d05222007@ntu.edu.tw

Spintronics has evolved from exploiting spin-polarized current to pure spin current. Interestingly, many spin current phenomena were first reported not in thin films but in bulk specimens. The specimen shape and associated demagnetizing field can significantly impact the spin current phenomenon. However, this important point has not been considered in previous studies. In this work, we demonstrated the strong influence of the demagnetizing field on the spin current transports, including the spin Seebeck effect, spin Hall magnetoresistance, and planar Hall resistance, in Pt/YIG. The calculated effective demagnetizing factors were closely related to the thickness- and width-dependent anomalous plateau behaviors. Furthermore, through magnetic force microscopy and angular-dependent PHE measurements, we observe the evolution of the magnetic domains with an abrupt 90° magnetic rotation.

Keywords: demagnetizing field, spin current transport, spin Seebeck effect, spin Hall magnetoresistance, magnetic anisotropy energy