Spin and Charge Interconversion in Dirac-Semimetal Thin Films

Wilson Yanez, Yongxi Ou, Run Xiao, Jahyun Koo, Jacob T. Held, Supriya Ghosh, Jeffrey Rable, Timothy Pillsbury, Enrique González Delgado, Kezhou Yang, Juan Chamorro, Alexander J. Grutter, Patrick Quarterman, Anthony Richardella, Abhronil Sengupta, Tyrel McQueen, Julie A. Borchers, K. Andre Mkhoyan, Binghai Yan, Nitin Samarth

Research output: Contribution to journalArticlepeer-review

Abstract

We use spin torque ferromagnetic resonance and ferromagnetic-resonance-driven spin pumping to detect spin-charge interconversion at room temperature in heterostructure devices that interface an archetypal Dirac semimetal, Cd3As2, with a metallic ferromagnet, Ni0.80Fe0.20 (permalloy). Angle-resolved photoemission directly reveals the Dirac-semimetal nature of the samples prior to device fabrication and high-resolution transmission electron microscopy is used to characterize the crystalline structure and the relevant heterointerfaces. We find that the spin-charge interconversion efficiency in Cd3As2/permalloy heterostructures is comparable to that in heavy metals and that it is enhanced by the presence of an interfacial oxide. Spin torque ferromagnetic resonance measurements reveal an in-plane spin polarization regardless of an oxidized or pristine interface. We discuss the underlying mechanisms for spin-charge interconversion by comparing our results with first principles calculations and conclude that extrinsic mechanisms dominate the observed phenomena. Our results indicate a need for caution in interpretations of spin-transport and spin-charge conversion experiments in Cd3As2 devices that seek to invoke the role of topological Dirac and Fermi arc states.

Original languageEnglish (US)
Article number054031
JournalPhysical Review Applied
Volume16
Issue number5
DOIs
StatePublished - Nov 2021

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

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