Colossal anisotropic absorption of spin currents induced by chirality

Rui Sun; Ziqi Wang; Brian P Bloom; Andrew H Comstock; Cong Yang; Aeron McConnell; Caleb Clever; Mary Molitoris; Daniel Lamont; Zhao-Hua Cheng; Zhe Yuan; Wei Zhang; Axel Hoffmann; Jun Liu; David H Waldeck; Dali Sun

doi:10.1126/sciadv.adn3240

Colossal anisotropic absorption of spin currents induced by chirality

Sci Adv. 2024 May 3;10(18):eadn3240. doi: 10.1126/sciadv.adn3240. Epub 2024 May 3.

Authors

Rui Sun^{1

2}, Ziqi Wang^{2

3}, Brian P Bloom⁴, Andrew H Comstock^{1

2}, Cong Yang^{2

3}, Aeron McConnell^{1

2}, Caleb Clever⁴, Mary Molitoris⁴, Daniel Lamont⁵, Zhao-Hua Cheng⁶, Zhe Yuan⁷, Wei Zhang⁸, Axel Hoffmann⁹, Jun Liu^{2

3}, David H Waldeck⁴, Dali Sun^{1

2}

Affiliations

¹ Department of physics, North Carolina State University, Raleigh, NC 27695, USA.
² Organic and Carbon Electronics Laboratories (ORaCEL), North Carolina State University, Raleigh, NC 27695, USA.
³ Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695, USA.
⁴ Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA.
⁵ Petersen Institute of Nanoscience and Engineering, University of Pittsburgh, Pittsburgh PA 15260, USA.
⁶ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
⁷ Department of Physics, Beijing Normal University, Beijing 100875, China.
⁸ Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
⁹ Department of Materials Science and Engineering and Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.

Abstract

The chiral induced spin selectivity (CISS) effect, in which the structural chirality of a material determines the preference for the transmission of electrons with one spin orientation over that of the other, is emerging as a design principle for creating next-generation spintronic devices. CISS implies that the spin preference of chiral structures persists upon injection of pure spin currents and can act as a spin analyzer without the need for a ferromagnet. Here, we report an anomalous spin current absorption in chiral metal oxides that manifests a colossal anisotropic nonlocal Gilbert damping with a maximum-to-minimum ratio of up to 1000%. A twofold symmetry of the damping is shown to result from differential spin transmission and backscattering that arise from chirality-induced spin splitting along the chiral axis. These studies reveal the rich interplay of chirality and spin dynamics and identify how chiral materials can be implemented to direct the transport of spin current.