Journal Club do Departamento de Física dos Materiais – FMT
Nesta semana o pós-graduando Marcos Henrique Lima de Medeiros, do Grupo Teórico de Materiais, apresentará o artigo: “Strong and Tunable Spin-Lifetime Anisotropy in Dual-Gated Bilayer Graphene”, Jinsong Xu et al.
Dia: 21 de novembro, quarta-feira, às 12h10.
Local: Sala de Seminários José Roberto Leite Edifício Alessandro Volta (bloco C).
Abstract:
We report the discovery of a strong and tunable spin-lifetime anisotropy with excellent out-of-plane spin lifetimes up to 7.8 ns at 100 K in dual-gated bilayer graphene. Remarkably, this realizes the manipulation of spins in graphene by electrically controlled spin-orbit fields, which is unexpected due to graphene’s weak intrinsic spin-orbit coupling (∼12 μeV). We utilize both the in-plane magnetic field Hanle precession and oblique Hanle precession measurements to directly compare the lifetimes of out-of-plane vs in-plane spins. We find that near the charge neutrality point, the application of a perpendicular electric field opens a band gap and generates an out-of-plane spin-orbit field that stabilizes out-of-plane spins against spin relaxation, leading to a large spin-lifetime anisotropy (defined as the ratio between out-of-plane and in-plane spin lifetime) up to ∼12 at 100 K. This intriguing behavior occurs because of the unique spin-valley coupled band structure of bilayer graphene. Our results demonstrate the potential for highly tunable spintronic devices based on dualgated 2D materials. https://doi.org/10.1103/PhysRevLett.121.127703
