Noncontact Spin Pumping by Microwave Evanescent Fields (Editors' Suggestion)

Image credit: [Tao Yu]

Abstract

The angular momentum of evanescent light fields has been studied in nano-optics and plasmonics but not in the microwave regime. Here we predict noncontact pumping of electron spin currents in conductors by the evanescent stray fields of excited magnetic nanostructures. The coherent transfer of the photon to the electron spin is proportional to the g factor, which is large in narrow gap semiconductors and surface states of topological insulators. The spin pumping current is chiral when the spin susceptibility displays singularities that indicate collective states. However, 1D systems with linear dispersion at the Fermi energy, such as metallic carbon nanotubes, are an exception since spin pumping is chiral even without interactions.

Publication
Phys. Rev. Lett 124, 236801 (2020)

Supplementary notes can be added here, including code and math.

Tao Yu
Tao Yu
Professor, Group Leader

My research interests include Magnetism, Spintronics, Unconventional superconductivity, Quantum transport in low dimensional electronics, and Strong light-matter interaction.

Related