エピタキシアル (Ga,Mn) Asマイクロデバイスにおける個々のドメイン壁の負の内在抵抗性
H X Tang1, S Masmanidis, R K Kawakami
1Condensed Matter Physics 114-36, California Institute of Technology, Pasadena, California 91125, USA.
Nature
|September 3, 2004
まとめ
研究者は,鉄磁性半導体内の個々の磁域壁 (DWs) が一貫して電気抵抗を低下させることを発見しました. (Ga,Mn) Asにおけるこの発見は,スピントロニックデバイスに関する洞察を提供します.
科学分野:
- マグネティズムとスピントロニクス
- 凝縮物質物理学 凝縮物質物理学
- マテリアルサイエンス 材料科学
背景:
- 磁気領域と磁気領域壁 (DWs) は磁気において極めて重要であり,スピントロニクスにおける応用がある.
- DW抵抗に関する既存の研究は矛盾する結果を生み出し,DW抵抗の根本的な性質を未解決のままにしています.
- フェロ磁性半導体は,スピントロニックのアプリケーションで金属の有望な代替品です.
研究 の 目的:
- 個々の磁域壁 (DWs) の内在抵抗を調査する.
- スピントロニクス研究のためのフェロ磁性半導体の可能性を調査する.
- DW抵抗に関する矛盾する実験的発見を解決する.
主な方法:
- モノクリスタリン (Ga,Mn) からパターン化されたマイクロデバイスをエピタキシアル層として利用する.
- 巨大な平面ホール効果を用いて,DWの伝播をリアルタイムで観測する.
- 磁場を適用して,高解像度の磁気抵抗測定のために個々のDWを正確に位置づけます.
主要な成果:
- (Ga,Mn) As.As.で一貫して観察された負の固有DW抵抗 (Ga,Mn)
- DW抵抗はチャネル幅に比例することを示した.
- 観測された負の抵抗を,磁気抵抗における量子修正に起因した.
結論:
- 鉄磁性半導体における個々の磁域壁は,負の内在抵抗を示す.
- この発見は,スピントロニックデバイスの開発に不可欠なDW行動のより明確な理解を提供します.
- この結果は,量子補正がこれらの材料の磁気抵抗を著しく影響することを示唆しています.
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