Group Seminar 2023/24

ABSTRACT: Spin-orbit torque (SOT) mechanism exhibits a huge potential for next generation spintronic devices. This has opened an avenue know as spin-orbitronics. Here on the one hand the spin to charge conversion in FM/HS heterostructure is very crucial, where FM and HS stand for ferromagnetic and high spin-orbit coupling (SOC) materials, respectively. On the other hand, the study of domain and skyrmion dynamics is also very important SOT based devices. In this context I will discuss first the topic of spin-to-charge conversion studied by inverse spin Hall effect (ISHE) with various HS materials such as heavy metals (Pt, Ta, W etc..), [1-3] topological insulators (e.g. Bi2Se3) [4,5], transition metal dichalcogenides (TMDs) [6] and antiferromagnets (viz. Mn2Au, Mn3Ga, IrMn, NiMn etc.) [6-9]. Further, in this talk I will review our recent results on the role of anisotropy [8], interactions, architecture, and interfaces on domain and skyrmion physics. Next, we discuss how the presence of interfacial Dzyaloshinskii-Moriya Interaction (DMI) originating from FM/HS interface plays a crucial role in stabilizing chiral spin textures viz. in magnetic thin films of CoFeB/Pt. [10-14] In the final part of the talk I will discuss interface induced phenomenon in FM/organic semiconductor (OSC) which is an emerging topic towards organic spintronics. Buckminsterfullerene (C60) is a potential candidate for organic spintronics due to many desirable properties viz. low spin orbit coupling, large spin diffusion length at room temperature etc. A magnetic interface (called as “spinterface”) can be created in the non-magnetic C60 due to charge transfer and interfacial hybridization. We show the effect of the magnetic C60 layer on the hysteresis loop shape and the domain images of the FM (Fe, Co or CoFeB) layers. We also study the change in magnetic anisotropy due to the presence of spinterface in these bilayer systems [15-18]. We will also discuss how DMI can emerge at the spinterface between Co/C60 interface [19]. At the end I will discuss the role of interface in enhancing the spin pumping in a CFB/β-W/C60 system. [20]

Acknowledgements: I sincerely express my thanks to my collaborators for their active participation and various funding agencies for the generous financial support to carry out this work.

References:

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[19] Pandey. ........Bedanta, et al., Physical Review Applied, 19, 044013 (2023)

[20] Sahoo……….Bedanta et al., Physical Review Applied, 21, 054001 (2024)