Enhancement of spin-to-charge conversion efficiency in topological insulators by interface engineering

Haoran He, Lixuan Tai, Di Wu, Hao Wu, Armin Razavi, Kin Wong, Yuxiang Liu, Kang L. Wang

Research output: Contribution to journalArticlepeer-review

Abstract

Topological insulator (TI) based heterostructure is a prospective candidate for ultrahigh spin-to-charge conversion efficiency due to its unique surface states. We investigate the spin-to-charge conversion in (Bi,Sb)2Te3 (BST)/CoFeB, BST/Ru/CoFeB, and BST/Ti/CoFeB by spin pumping measurement. We find that the inverse Edelstein effect length (λIEE) increases by 60% with a Ru insertion while remains constant with a Ti insertion. This can be potentially explained by the protection of BST surface states due to the high electronegativity of Ru. Such enhancement is independent of the insertion layer thickness once the thickness of Ru is larger than 0.5 nm, and this result suggests that λIEE is very sensitive to the TI interface. In addition, an effectively perpendicular magnetic anisotropy field and additional magnetic damping are observed in the BST/CoFeB sample, which comes from the interfacial spin-orbit coupling between the BST and the CoFeB. Our work provides a method to enhance λIEE and is useful for the understanding of charge-to-spin conversion in TI-based systems.

Original languageEnglish
Article number071104
JournalAPL Materials
Volume9
Issue number7
DOIs
Publication statusPublished - 2021 Jul 1

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Engineering(all)

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