Electrical Manipulation and Detection of Magnetization in Magnetic Insulators with Perpendicular Anisotropy

Can Onur Avci, ETH Zürich

August 4, 2020

Magnetic insulators (MIs) host an array of attractive properties for spintronics research and potential applications. Some prominent examples are tunable saturation magnetization, and perpendicular anisotropy, low damping, long magnon diffusion lengths, and highly ordered single crystal structure that could be beneficial for obstacle-free domain wall and skyrmion motion. However, electrically manipulating and detecting the magnetization in MIs, which is a prerequisite for spintronic devices, has been impossible for a long time due to the lack of physical phenomena to do so. Recent advances in spin current generation and detection have provided the relevant tools to detect the magnetization vector of MIs by purely electrical means [1-3]. Consequently, the research into MIs has gained significant momentum in the past decade.

In this seminar, we will discuss some of the recent progress in insulator spintronics research. First, we will overview the experiments of current-induced switching and electrical detection of magnetization state in MIs with perpendicular anisotropy [4,5]. We will then discuss the magnetic textures and current-driven dynamics of domain walls in rare-earth iron garnets. We will show how chiral magnetic interactions stabilizes Néel DWs in ultrathin MIs, which can be propelled very fast by spin-orbit torques [6-9]. Finally, we will discuss a thermoelectric effect that we have recently discovered, which allows electrical detection of the out-of-plane magnetization component in magnetic insulators in a nonlocal device geometry [10].

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[2] Uchida et al. Appl. Phys. Lett. 97, 172505 (2010).
[3] Cornelissen et al. Nat. Phys. 11, 1022 (2015).
[4] Avci et al. Nat. Mater. 16, 309 (2017).
[5] Shao et al. Nat. Commun. 9, 3612 (2018).
[6] Avci et al. Nat. Nanotech. 14, 561 (2019).
[7] Velez et al. Nat. Commun. 10, 4750 (2019).
[8] Ding et al. Phys. Rev. B 100, 100406(R) (2019).
[9] Caretta et al. Nat. Commun. 11, 1090 (2020).
[10] Avci et al. Phys. Rev. Lett. 124, 027701 (2020).