Physics

Nanotechnology

Fluence

Nanoscopic scale

Laser

Mechanics

Ferromagnetism

Skyrmion

Operating system

Optics

Bubble

Spintronics

Acoustics

Ultrashort pulse

Materials science

Condensed matter physics

Lattice (music)

Magnetic storage

Computer science

Racetrack memory

Quantum mechanics

Memory refresh

Computer memory

Semiconductor memory

Nano Letters

Magnetic skyrmions are topologically nontrivial spin textures which hold great promise as stable information carriers in spintronic devices at the nanoscale. One of the major challenges for developing novel skyrmion-based memory and logic devices is fast and controlled creation of magnetic skyrmions at ambient conditions. Here we demonstrate the single ultrafast (35-fs) laser pulse-induced generation of skyrmion bubbles and skyrmion bubble lattices from a ferromagnetic state in sputtered ultrathin magnetic films at room temperature. The skyrmion bubble density increases with the laser fluence in a controlled way, and it finally becomes saturated, forming disordered hexagonal lattices. Moreover, we present that the skyrmion bubble lattice configuration leads to enhanced topological stability as compared to isolated skyrmions, suggesting its promising use in data storage. Our findings shed light on the optical approach to the skyrmion bubble lattice in commonly accessible materials, paving the road toward the emerging skyrmion-based memory and synaptic devices.

Creation of Magnetic Skyrmion Bubble Lattices by Ultrafast Laser in Ultrathin Films