Electrical and thermal generation of spin currents by magnetic bilayer graphene

• Published in: Nature nanotechnology Vol. 16; no. 7; pp. 788 - 794
• Main Authors: Ghiasi, Talieh S., Kaverzin, Alexey A., Dismukes, Avalon H., de Wal, Dennis K., Roy, Xavier, van Wees, Bart J.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 06.05.2021; Nature Publishing Group
• Subjects: 142/126; 639/766/119/1001; 639/766/119/2793; 639/766/119/997; 639/925/918/1052; 639/925/927/1062; Antiferromagnetism; Bilayers; Carrier mobility; Chemistry and Materials Science; Conductivity; Coupling; Current carriers; Electrons; Graphene; Interlayers; Magnetism; Materials Science; Memory devices; Nanotechnology; Nanotechnology and Microengineering; Polarization; Polarization (spin alignment); Science & Technology - Other Topics; Seebeck effect; Two dimensional materials
• ISSN: 1748-3387; 1748-3395
• DOI: 10.1038/s41565-021-00887-3

Ultracompact spintronic devices greatly benefit from the implementation of two-dimensional materials that provide large spin polarization of charge current together with long-distance transfer of spin information. Here spin-transport measurements in bilayer graphene evidence a strong spin–charge coupling due to a large induced exchange interaction by the proximity of an interlayer antiferromagnet (CrSBr). This results in the direct detection of the spin polarization of conductivity (up to 14%) and a spin-dependent Seebeck effect in the magnetic graphene. The efficient electrical and thermal spin–current generation is the most technologically relevant aspect of magnetism in graphene, controlled here by the antiferromagnetic dynamics of CrSBr. The high sensitivity of spin transport in graphene to the magnetization of the outermost layer of the adjacent antiferromagnet, furthermore, enables the read-out of a single magnetic sublattice. The combination of gate-tunable spin-dependent conductivity and Seebeck coefficient with long-distance spin transport in a single two-dimensional material promises ultrathin magnetic memory and sensory devices based on magnetic graphene. Graphene promises long-distance transfer of spin information with concomitant high charge carrier mobility. Proximity coupling of bilayer graphene with the 2D interlayer antiferromagnetic CrSBr now enables active generation of spin currents in graphene both electrically and thermally.