講演情報
[8p-E207-3]Giant Magnetoresistance and Anomalous Hall Effect in Magnetic-Insulator-Based Spin Switches
〇Hisakazu Matsuki1,2, Guang Yang2,3, Jiahui Xu2, Vitaly Golovach4, Yu He3, Jiaxu Li3, Alberto Hijano4, Niladri Banerjee5, Iuliia Alekhina2, Nadia Stelmashenko2, Sebastian Bergeret4, Jason W. A. Robinson2 (1.ICR, Kyoto Univ., 2.Univ. of Cambridge, 3.Beihang Univ., 4.UPV/EHU, 5.Imperial Coll. London)
キーワード：
Ferromagnetic insulator、Giant Magnetoresistance、Weak Antilocalization
Magnetic-insulator/nonmagnetic-metal (MI/N) interfaces have attracted considerable attention owing to spin-transport phenomena such as spin Hall magnetoresistance (SMR) [1]. In contrast, giant magnetoresistance (GMR) is typically observed in multilayers containing metallic ferromagnets [2,3], and its realization in magnetic-insulator-based systems remains rare. In this study, we fabricated EuS(20 nm)/Au(d)/EuS(10 nm) spin switches consisting of the ferromagnetic insulator EuS and the nonmagnetic metal Au, and investigated their magnetotransport properties for Au thicknesses ranging from 4 to 28 nm. For thin Au layers, a positive magnetoresistance originating from weak antilocalization was observed. As the Au thickness increased, the magnetoresistance reversed sign and evolved into a GMR-like response, where the antiparallel magnetic configuration exhibited a higher resistance than the parallel configuration. This behavior indicates a crossover from quantum-interference-dominated transport to spin-dependent scattering. Furthermore, a pronounced anomalous Hall effect was observed over the entire Au thickness range. The magnitude of the anomalous Hall resistivity decreased with increasing Au thickness and can be quantitatively explained by a spin-dependent momentum-scattering model induced by the interfacial exchange field at the EuS/Au interfaces. These results demonstrate that interfacial exchange fields can generate both giant magnetoresistance and anomalous Hall effects. Moreover, the anomalous Hall response is difficult to reconcile with conventional SMR mechanisms, suggesting a distinct spin-transport phenomenon driven by interfacial exchange fields.1. J. M. Gomez-Perez, et al. Nano Lett. 20, 6815–6823 (2020).
2. M. N. Baibich, et al. Phys. Rev. Lett. 61, 2472–2475 (1988).
3. G. Binasch, et al. Phys. Rev. B 39, 4828–4830 (1989).
2. M. N. Baibich, et al. Phys. Rev. Lett. 61, 2472–2475 (1988).
3. G. Binasch, et al. Phys. Rev. B 39, 4828–4830 (1989).