Optically induced electron spin currents in the Kretschmann configuration

Abstract: We investigate electron spin currents induced optically via plasmonic modes in the Kretschmann configuration. By utilising the scattering matrix formalism, we take the plasmonic mode coupled to external laser drive into consideration and calculate induced magnetisation in the metal. The spatial distribution of the plasmonic mode is inherited by the induced magnetisation, which acts as inhomogeneous effective magnetic field and causes the Stern-Gerlach effect to drive electron spin currents in the metal. We solve spin diffusion equation with a source term to analyse the spin current as a function of the spin diffusion length of the metal, the frequency and the incident angle of the external drive.