Optical Cooling of Magnons

Sanchar Sharma, Yaroslav M. Blanter, and Gerrit E. W. Bauer

Phys. Rev. Lett. 121, 087205 – Published 22 August 2018

Abstract

Inelastic scattering of light by spin waves generates an energy flow between the light and magnetization fields, a process that can be enhanced and controlled by concentrating the light in magneto-optical resonators. Here, we model the cooling of a sphere made of a magnetic insulator, such as yttrium iron garnet, using a monochromatic laser source. When the magnon lifetimes are much larger than the optical ones, we can treat the latter as a Markovian bath for magnons. The steady-state magnons are canonically distributed with a temperature that is controlled by the light intensity. We predict that such a cooling process can significantly reduce the temperature of the magnetic order within current technology.

Received 10 April 2018

DOI:https://doi.org/10.1103/PhysRevLett.121.087205

Physics Subject Headings (PhySH)

Light-induced magnetic effects Magnons

Ferromagnets Magnetic insulators Optical microcavities

Adiabatic approximation Rotating wave approximation Stochastic differential equations

Atomic, Molecular & OpticalCondensed Matter, Materials & Applied Physics

Authors & Affiliations

Sanchar Sharma¹, Yaroslav M. Blanter¹, and Gerrit E. W. Bauer^2,1

¹Kavli Institute of NanoScience, Delft University of Technology, 2628 CJ Delft, The Netherlands
²Institute for Materials Research & WPI-AIMR & CSRN, Tohoku University, Sendai 980-8577, Japan