顕微鏡内でのスピンの超高速制御(Ultrafast control of spins in a microscope)


ドイツ連邦工科大学の研究者らは、渦巻き状に配置された一握りのスピンの回転を可視化し、史上最速で制御する新技術を開発しました。この技術は、新しいタイプのコンピューター・メモリー、論理ゲート、高精度センサーなどを含む「スピントロニクス」を発展させる可能性があります。 Researchers at EPFL have developed a new technique that can visualize and control the rotation of a handful of spins arranged in a vortex-like texture at the fastest speed ever achieved. The breakthrough can advance “spintronics”, a technology that includes new types of computer memory, logic gates, and high-precision sensors.

2023-01-27 スイス連邦工科大学ローザンヌ校(EPFL)



スキルミオン結晶の超高速コヒーレント制御のイメージング Imaging the Ultrafast Coherent Control of a Skyrmion Crystal

Phoebe Tengdin, Benoit Truc, Alexey Sapozhnik, Lingyao Kong, Nina del Ser, Simone Gargiulo, Ivan Madan, Thomas Schönenberger, Priya R. Baral, Ping Che, Arnaud Magrez, Dirk Grundler, Henrik M. Rønnow, Thomas Lagrange, Jiadong Zang, Achim Rosch, and Fabrizio Carbone
Physical Review X  Published 20 December 2022

Figure 1


Exotic magnetic textures emerging from the subtle interplay between thermodynamic and topological fluctuation have attracted intense interest due to their potential applications in spintronic devices. Recent advances in electron microscopy enable the imaging of random photogenerated individual skyrmions. However, their deterministic and dynamical manipulation is hampered by the chaotic nature of such fluctuations and the intrinsically irreversible switching between different minima in the magnetic energy landscape. Here, we demonstrate a method to coherently control the rotation of a skyrmion crystal by discrete amounts at speeds which are much faster than previously observed. By employing circularly polarized femtosecond laser pulses with an energy below the band gap of the Mott insulator Cu2OSeO3, we excite a collective magnon mode via the inverse Faraday effect. This triggers coherent magnetic oscillations that directly control the rotation of a skyrmion crystal imaged by cryo-Lorentz transmission electron microscopy. The manipulation of topological order via ultrafast laser pulses shown here can be used to engineer fast spin-based logical devices.