Microwave

Quantum mechanics

Magnetic field

Texture (cosmology)

Spin (aerodynamics)

Magnetization

Skyrmion

Computer science

Demagnetizing field

Thermodynamics

Physics

Image (mathematics)

Resonance (particle physics)

Condensed matter physics

Artificial intelligence

Nucleation

Micromagnetics

Physical Review Letters

We have deterministically created a stable topological spin texture in magnetic tunnel junctions (MTJ) by using pulsed or microwave currents. The spin texture is characterized by a field-dependent intermediate resistance state and a new magnetic resonance. Micromagnetic simulations show that the observations are consistent with the nucleation of a single skyrmion, facilitated by a spatially nonuniform stray field. The unique resonance spectrum is identified as the skyrmion breathing mode and a skyrmion diameter of 75 nm is estimated. This work shows the possibility to create skyrmions in MTJs without the Dzyaloshinskii-Moriya interaction and could lead to noninvasive, on-chip skyrmion measurement.

Experimental Observation of Single Skyrmion Signatures in a Magnetic Tunnel Junction