Spin-transfer-torque excitations in ferromagnetic nanostructures: spin torque oscillators
CIC nanoGUNE Seminars
- Speaker
-
Ferran Macia, Universitat Barcelona, Barcelona, Spain
- When
-
2014/09/22
13:00 - Place
- nanoGUNE seminar room, Tolosa Hiribidea 76, Donostia - San Sebastian
- Add to calendar
- iCal
**Host** : L.Hueso
Controlling the dynamics of magnetization in ferromagnetic (FM) thin films is
essential to a new generation of wave-computing and on-chip communication
devices working at high frequency and low power. Nanometer scale electrical
contacts to ferromagnetic thin films (STNOs) can carry sufficient current
densities to excite magnetization dynamics through the spin-transfer-torque
effect resulting in either localized or propagating short wavelength spin
waves. In this talk I will overview the spin-transfer-torque magnetic
excitations in ferromagnetic thin films and focus on the spin waves and the
dynamics created by STNOs.
I will review some applications of spin-wave patterns created from STNOs and
their interactions with background oscillations. I will show you some recent
results on imaging localized excitations ~100nm with XMCD microscopy.
We will also discuss recent advances in the study of magnetic droplet solitons
(excitations of reversed spins that are strongly localized precess in-phase).
In this presentation I will show that magnetic droplet solitons can be
stabilized in a spin transfer nanocontact, exhibiting a strong hysteretic
response to fields and currents and a nearly fully reversed magnetization.
These observations, in addition to their fundamental interest, open up new
applications for magnetic droplet solitons as multi-state high frequency
current and field tunable oscillators.
[1] F. Macià et al. Nanotechnology 22 095301 (2011)
[2] F. Macià et al. Nanotechnology 25 045303 (2014)
[3] S. M. Mohseni et al., Science 339, 1295 (2013)
[4] F. Macià et al. arXiv:1408.1902 (2014)