Effects of dephasing on spin lifetime in ballistic spin-orbit materials

Abstract

We theoretically investigate spin dynamics in spin-orbit-coupled materials. In the ballistic limit, the spin lifetime is dictated by dephasing that arises from energy broadening plus a nonuniform spin precession. For the case of clean graphene, we find a strong anisotropy with spin lifetimes that can be short even for modest energy scales, on the order of a few ns. These results offer deeper insight into the nature of spin dynamics in graphene, and are also applicable to the investigation of other systems where spin-orbit coupling plays an important role. ; This work is supported by the European Union Seventh Framework Programme under grant agreement 604391 Graphene Flagship, the Severo Ochoa Program (MINECO, Grant SEV-2013-0295), the Spanish Ministry of Economy and Competitiveness (MAT2012-33911), and Secretaría de Universidades e Investigación del Departamento de Economía y Conocimiento de la Generalidad de Cataluña. ; Peer Reviewed