2023/07/21 by Saba Karimeddiny, Karimeddiny, Saba, Thow Min Jerald Cham +7
Engineering · Physics and Astronomy · #Characterization and Applications of Magnetic Nanoparticles #FOS: Physical sciences #Force Microscopy Techniques and Applications #Magneto-Optical Properties and Applications #Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
paper · pdf · doi:10.48550/arxiv.2307.11624
openalex publication_date 2023/07/21 · openalex created_date 2023/07/25 · openalex updated_date 2026/08/02
Sagnac interferometry can provide a significant improvement in signal-to-noise ratio compared to conventional magnetic imaging based on the magneto-optical Kerr effect (MOKE). We show that this improvement is sufficient to allow quantitative measurements of current-induced magnetic deflections due to spin-orbit torque even in thin-film magnetic samples with perpendicular magnetic anisotropy for which the Kerr rotation is second-order in the magnetic deflection. Sagnac interfermometry can also be applied beneficially for samples with in-plane anisotropy, for which the Kerr rotation is first order in the deflection angle. Optical measurements based on Sagnac interferometry can therefore provide a cross-check on electrical techniques for measuring spin-orbit torque. Different electrical techniques commonly give quantitatively inconsistent results, so that Sagnac interferometry can help to identify which techniques are affected by unidentified artifacts.