- Bonetti, S
- Kukreja, R
- Chen, Z
- Macià, F
- Hernàndez, JM
- Eklund, A
- Backes, D
- Frisch, J
- Katine, J
- Malm, G
- Urazhdin, S
- Kent, AD
- Stöhr, J
- Ohldag, H
- Dürr, HA
- et al.
Spin waves, the collective excitations of spins, can emerge as nonlinear solitons at the nanoscale when excited by an electrical current from a nanocontact. These solitons are expected to have essentially cylindrical symmetry (that is, s-like), but no direct experimental observation exists to confirm this picture. Using a high-sensitivity time-resolved magnetic X-ray microscopy with 50 ps temporal resolution and 35 nm spatial resolution, we are able to create a real-space spin-wave movie and observe the emergence of a localized soliton with a nodal line, that is, with p-like symmetry. Micromagnetic simulations explain the measurements and reveal that the symmetry of the soliton can be controlled by magnetic fields. Our results broaden the understanding of spin-wave dynamics at the nanoscale, with implications for the design of magnetic nanodevices.