[26p-E201-1~12] 10.2 スピン基盤技術・萌芽的デバイス技術

▼ [26p-E201-4] Sign reversal of unidirectional spin Hall magnetoresistance in ferrimagnetic CoGd films

〇Kento Hasegawa^1,2、Yuki Hibino³、Tomohiro Koyama^2,4,5、Daichi Chiba^2,4 (1.The Univ. of Tokyo、2.Sanken, Osaka Univ.、3.AIST、4.CSRN, Osaka Univ.、5.PRESTO, JST)

キーワード：spin Hall magnetoresistance, ferrimagnetic, nonreciprocal transport

The recently discovered unidirectional spin Hall magnetoresistance (USMR) in a heavy metal/ferromagnet heterostructure is a nonreciprocal phenomenon, in which the longitudinal resistance depends on the current direction. The resistance change due to USMR relies on the relative angle between the magnetization and the spin polarization direction of the transverse spin current induced by the spin Hall effect. As a plausible origin of USMR, the spin-dependent scattering has been proposed in analogy to the giant magnetoresistance (GMR). Although the close similarity between USMR and GMR has been pointed out since the discovery of USMR, there have been few reports that experimentally confirm this similarity. In this study, we investigate the composition and temperature dependences of USMR in W/CoGd heterostructures since the ferrimagnetic CoGd alloy is known to cause a sign reversal of the GMR around its magnetization compensation point.