Large angle amplitude "spin strain waves"
DIPC Seminars
- Speaker
-
Lucia Aballe, ALBA Synchrotron Light Facility
- When
-
2019/01/17
13:00 - Place
- Donostia International Physics Center
- Add to calendar
- iCal
Surface Acoustic Waves (SAW) are propagating strain waves that can be
generated through oscillating electric fields at the surface of piezoelectric
materials. They can couple to a magnetic material in heterostructures
comprising both a piezoelectric and a magnetic material. The mutual coupling
of SAW and magnetic material through strain and magnetoelasticity has been
mostly investigated by averaging or indirect methods [1-4] which could not
resolve the dynamics of the interaction.
Using stroboscopic XPEEM with X-ray circular magnetic dichroism (XMCD)
contrast, we have previously investigated the dynamic response of magnetic
flux closure states in patterned nanostructures upon excitation with a SAW
which is synchronized to the 500 MHz repetition rate of the ALBA synchrotron
[5].
In this talk I present our studies on “strain spin waves†over macroscopic
areas in continuous nickel thin films, deposited onto piezoelectric substrates
(LiNbO3) capable to produce directional SAW. By exciting with different SAW
frequencies (125 MHz - 500 MHz), we have directly imaged collective magnetic
excitations with large angular modulation of the magnetization and with the
spatial periodicity of the corresponding SAW. These coupled modes propagate
over mm long distances thanks to the SAW and provide interesting perspectives
for the development of magnonic devices.
References
[1] S. Davis et al., Appl. Phys. Lett. 97, 232507 (2010).
[2] M. Weiler et al., Phys. Rev. Lett. 106, 117601 (2011).
[3] M. Weiler et al., Phys. Rev. Lett. 108, 176601 (2012).
[4] L. Thevenard et al., Phys. Rev. B 90, 094401 (2014).
[5] M. Foerster et al. Nat. Comm. 8, 407 (2017).
Host: Celia Rogero