熱伝導量の量子を測定する

Schwab¹, Henriksen, Worlock

¹Condensed Matter Physics, California Institute of Technology, Pasadena 91125, USA.

Nature

|May 9, 2000

まとめ

科学者は,ナノ構造を隔離する量子化された熱伝導性を観察しました. この発見は,1次元弾道的なフォノン輸送の理論を支持し,電気伝導量の定量化を反映しています.

科学分野:

メソスコープ物理学のメソスコープ物理学
凝縮物質物理学凝縮物質物理学
ナノスケールの熱輸送

背景:

メソスコピック電子システムは,サンプル寸法のスケールで量子効果が顕著になる現象を示しています.
電気伝導量の定量化,重要なメソスコピック効果は,準一次元収縮で観察されます.
メソスコピックフォノン系における熱伝送の類似した定量化行動は理論化されているが,実験的に確認されていない.

研究の目的:

メソスコピックフォノン系における量子化された熱伝導の可能性を調査する.
一次元の弾道チャンネルにおける熱輸送に関する理論的予測を実験的に検証する.

主な方法:

実験は,非常に低い温度で,吊り下げられた絶縁ナノ構造物で実施されました.
測定は,これらのナノ構造物の熱伝導率 (Gth) を決定することに焦点を当てました.

主要な成果:

この研究では,熱伝導度 (Gth) の定量化限界値の観測が報告されています.
観測された熱伝導性の振る舞いは,一次元弾道的なフォノン輸送の予測と一致しています.
低温では,Gthは熱伝導性の普遍量子に近づく,g0 = pi^2*kB^2*T/3hである.

結論:

この発見は,メソスコピックフォノン系における量子化された熱伝導性を実証している.
この観測は,一次元弾道的なフォノン輸送の実験的証拠を提供します.
この結果は,ナノ構造における量子熱伝送の理論モデルを検証している.

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