Abstract
Phase-coherent spin waves can be generated by magnetic field pulse, spin current pulse, or optical pulse. Here we use optical spin-orbit torque, originating from the conversion of an optical pulse into a spin-polarized current pulse, to excite spin waves in the frequency range from GHz to THz. We investigate the frequency, amplitude, and damping of the spin waves of Co thin films. From the frequency analysis, we determine the stiffness of Co spin waves to be 5meVnm2. From the amplitude analysis, we show that the Co layer acts as a cavity for spin waves. From the damping analysis, we observe that the damping enhancement due to the spin pumping effect is about two times larger in spin waves than in uniform precession.
| Original language | English |
|---|---|
| Article number | 014437 |
| Journal | Physical Review B |
| Volume | 102 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 2020 Jul 1 |
Bibliographical note
Funding Information:G.-M.C. acknowledges the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (NRF-2019R1C1C1009199) and the Creative Materials Discovery Program through the National Research Foundation of Korea (NRF) funded by Ministry of Science and ICT (2018M3D1A1058793). K.-J.L. acknowledges the NRF (NRF-2020R1A2C3013302). H.-W.L. acknowledges the NRF (NRF-2020R1A2C2013484).
Publisher Copyright:
© 2020 American Physical Society.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics