2025-04-10 東北大学
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図1. (a)～(c)水平方向に約147画素、水平方向に約74画素、垂直方向に約98画素ごとに2πの位相シフトを誘起する入力電圧をSLMに印加し、試料から反射されたポンプビームの光から円偏光成分S₃/S₀を抽出した。(d)-(f)それぞれ(a)-(c)に対応する励起直後のt=0 psにおけるカー信号の空間マップ。
＜関連情報＞
- https://www.tohoku.ac.jp/japanese/2025/04/press20250410-02-spin.html
- https://www.tohoku.ac.jp/japanese/newimg/pressimg/tohokuuniv-press20250410_02_spin.pdf
- https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.23.044017
半導体二次元電子ガス中のプログラマブル構造化光を用いた任意のスピンらせんのダイレクトインプリンティング Direct imprinting of arbitrary spin helices using programmable structured light in a semiconductor two-dimensional electron gas
Keito Kikuchi, Jun Ishihara, Miari Hiyama, Sota Yamamoto, Yuzo Ohno, Takachika Mori, Kensuke Miyajima, and Makoto Kohda
Physical Review Applied Published: 7 April, 2025
DOI: https://doi.org/10.1103/PhysRevApplied.23.044017
Abstract
Precise control of spatial spin structures, such as spin helices, is critical for advancing spintronic devices, particularly in nonvolatile low-power information storage and processing. Conventional techniques, including transient spin-grating spectroscopy and spatial- and time-resolved Kerr rotation microscopy, are limited by fixed optical grating periods and uniform light polarization, respectively, which constrain the flexibility of spin helix generation. Here, we introduce an alternative approach utilizing programmable structured light to directly imprint spatial spin structures in a Ga As/(Al,Ga) As quantum well. This method allows for precise control over the wave number and configuration of the spin helices, overcoming the limitations of previous techniques. Experiments conducted using pump-probe Kerr rotation microscopy combined with a programmable spatial light modulator revealed the efficient and tunable generation of spin helices. This approach is broadly applicable not only to semiconductors but also to magnetic thin films and two-dimensional materials.
