PCSI2026 Session PCSI-WeA1: Spin Transport

Wednesday, January 28, 2026 2:00 PM in Ballroom South

Wednesday Afternoon

Start	Invited?	Item
2:00 PM	Invited	PCSI-WeA1-1 Emergent Spintronic Functionalities in Correlated Oxide Heterostructures Shinobu Ohya (The University of Tokyo) Spintronics promises low-power, multifunctional electronics in which electron spin enables both logic and memory operations. Among the various proposed devices, spin transistors are particularly attractive for non-volatile computing. Key milestones toward their practical realization include the demonstration of large spin-valve effects and the achievement of efficient spin-charge interconversion, both of which are vital for energy-efficient operation. Perovskite oxides provide a versatile materials platform owing to their nearly matched lattice constants, which allow the fabrication of high-quality all-epitaxial heterostructures essential for coherent spin control in devices. These correlated oxides exhibit emergent functionalities, such as two-dimensional transport with strong spin–orbit coupling, metal–semiconductor transitions, topological states, and spin Hall effects, thereby offering unique opportunities for spintronics applications. We first demonstrate a giant planar spin-valve effect in (La_0.67,Sr_0.33)MnO₃ (LSMO)-based spin-MOSFETs, where oxygen-vacancy engineering creates nanoscale Mott-semiconducting regions, yielding magnetoresistance ratios of ~140% [1] — over two orders of magnitude higher than those of conventional Si-based spin-MOSFETs. Second, we show highly efficient spin-to-charge conversion in the two-dimensional electron gas formed at the strongly correlated LaTiO_3+δ (LTO)/SrTiO₃ interface, achieving a record conversion efficiency (referred to as the inverse Edelstein length) of ~190 nm [2]. This performance originates from Rashba spin–orbit coupling combined with reduced spin scattering in correlated metallic LTO. Finally, in the Weyl ferromagnet SrRuO₃ (SRO), subtle oxygen-octahedral rotations generate spin Berry curvature that drives spin–orbit torque magnetization switching in a single-layer device [3]. Magnetization reversal occurs at current densities an order of magnitude lower than those required in conventional bilayer systems, without the need for heavy-metal layers. These studies were partly supported by Grants-in-Aid for Scientific Research, ERATO of JST, and the Spintronics Research Network of Japan (Spin-RNJ).[1] T. Endo, S. Ohya et al., Adv. Mater. 35, 2300110 (2023). [2] S. Kaneta-Takada, S. Ohya et al., Nat. Commun. 13, 5631 (2022).[3] H. Horiuchi, S. Ohya et al., Adv. Mater. 37, 2416091 (2025). View Supplemental Document (pdf)
2:40 PM		PCSI-WeA1-9 Annealing Effects on the High-Temperature Magnetic Properties of Ta/CoFeB/Ta Films Hyejin Son, Byeongwoo Kang, Ji-Hyeon Kwon (Korea University) Soft magnetic Cobalt–iron–boron (CoFeB) thin films have attracted significant interest for spintronic applications due to its high saturation magnetization and spin polarization. The structural and magnetic properties of CoFeB thin films are strongly influenced by sputtering power [1], post-annealing treatments [2], and variations in CoFeB layer thickness [3]. Spintronic devices operate at elevated temperatures, where thermal effects can alter magnetic damping. Since damping determines switching speed and power consumption, understanding its variation within the operating temperature range is crucial. Most experimental studies of CoFeB films have been limited to room-temperature measurements [4], which cannot provide a systematic understanding of their temperature-dependent damping. In this study, we investigate the high-temperature magnetic properties of CoFeB thin films with different annealing conditions. Ta (5 nm)/Co₂₀Fe₆₀B₂₀ (35 nm)/Ta (3 nm) structures with different annealing conditions (as-deposited, 200 °C, 300 °C, and 400 °C) were measured by ferromagnetic resonance (FMR) spectroscopy at temperatures ranging from 30-160°C to extract the linewidth and resonance magnetic field for dynamic property analysis (Fig. 1). The raw FMR spectra of the 300 °C annealed sample measured at 160 °C showed a monotonic increase in both the resonance field and linewidth with increasing frequency (Fig. 1(a)). The normalized FMR spectra at a fixed frequency of 14 GHz exhibited a gradual increase in both parameters with temperature (Fig. 1(b)). Analysis of the linewidth further showed that the Gilbert damping constant α decreases in the annealed samples compared with the as-deposited film (Fig. 1(c)). The effects of annealing on the high-temperature magnetic response of symmetric Ta/CoFeB/Ta multilayers will be further discussed. View Supplemental Document (pdf)
2:45 PM	Invited	PCSI-WeA1-10 Magneto-Optical Detection of Orbital Hall Effect Kyung-Hun Ko (Sungkyunkwan University); Daegeun Jo, Peter Oppeneer (Uppsala University); Hyun-Woo Lee (POSTECH); Gyung-Min Choi (Sungkyunkwan University) Orbital Hall effect (OHE) refers to the generation of electron orbital angular momentum flow transverse to an external electric field. Theories predict strong OHE in various transition metals of 3d, 4d, and 5d bands [1-3]. In a weak spin-orbit coupling system of 3d metals, OHE can be dominant over spin Hall effect (SHE). To detect OHE, we measured the current-driven orbital accumulation at surfaces of 3d metals of Ti, Mn, and Cu [4-6]. Using the longitudinal magneto-optical Kerr effect (MOKE), we simultaneously detected the in-plane-polarized orbital moments driven by OHE and out-of-plane-polarized orbital moments driven by Oersted field. From the relative comparison of the in-plane and out-of-plane orbital moments, we quantified the magnitude of the OHE-driven orbital accumulation. From the thickness dependence, we distinguished the bulk contribution of OHE and interfacial contribution of orbital Rashba-Edelstein effect (OREE) and determined the orbital diffusion length. [1] H. Kontani, T. Tanaka, D. S. Hirashima, K, Yamada, and J. Inoue, Phys. Rev. Lett. 102, 016601 (2009) [2] D. Go, D. Jo, C. Kim, and H.-W. Lee, Phys. Rev. Lett. 121, 086602 (2018) [3] L. Salemi and P. M. Oppeneer, Phys. Rev. Mater. 6, 095001 (2022) [4] Y.-G. Choi et al., Nature 619, 52 (2023) [5] K.-H. Ko et al., submitted [6] K.-H. Ko et al., submitted View Supplemental Document (pdf)
3:25 PM		Coffee Break & Poster Viewing