Nonlocal Spin Dynamics in the Crossover from Diffusive to Ballistic Transport

Improved fabrication techniques have enabled the possibility of ballistic transport and unprecedented spin manipulation in ultraclean graphene devices. Spin transport in graphene is typically probed in a nonlocal spin valve and is analyzed using spin diffusion theory, but this theory is not necessar...

Descripción completa

Detalles Bibliográficos
Autores: Vila Tusell, Marc|||0000-0001-9118-421X, Garcia, José H.|||0000-0002-5752-4759, Cummings, Aron|||0000-0003-2307-497X, Power, Stephen|||0000-0003-4566-628X, Groth, Christoph W., Waintal, Xavier|||0000-0003-3816-8290, Roche, Stephan|||0000-0003-0323-4665
Tipo de recurso: artículo
Fecha de publicación:2020
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:230698
Acceso en línea:https://ddd.uab.cat/record/230698
https://dx.doi.org/urn:doi:10.1103/PhysRevLett.124.196602
Access Level:acceso abierto
Palabra clave:Ballistic transports
Fabrication technique
Nonlocal spin valves
Quantum simulations
Spin manipulation
Spin-diffusion length
Theoretical framework
Two-dimensional materials
Descripción
Sumario:Improved fabrication techniques have enabled the possibility of ballistic transport and unprecedented spin manipulation in ultraclean graphene devices. Spin transport in graphene is typically probed in a nonlocal spin valve and is analyzed using spin diffusion theory, but this theory is not necessarily applicable when charge transport becomes ballistic or when the spin diffusion length is exceptionally long. Here, we study these regimes by performing quantum simulations of graphene nonlocal spin valves. We find that conventional spin diffusion theory fails to capture the crossover to the ballistic regime as well as the limit of long spin diffusion length. We show that the latter can be described by an extension of the current theoretical framework. Finally, by covering the whole range of spin dynamics, our study opens a new perspective to predict and scrutinize spin transport in graphene and other two-dimensional material-based ultraclean devices.