グラフェンのディラク点近くの巨大な非局所性
D A Abanin1, S V Morozov, L A Ponomarenko
1Manchester Centre for Mesoscience and Nanotechnology, University of Manchester, Manchester M13 9PL, UK.
Science (New York, N.Y.)
|April 16, 2011
まとめ
室温でも,グラフェン輸送測定で非局所的な有意な反応が観察されました. この効果は,スピン/渓谷電流と関連しており,グラフェンを理解する上で極めて重要です.
科学分野:
- 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
- ナノテクノロジー ナノテクノロジー
背景:
- 輸送測定は,グラフェンの電子現象を明らかにするために不可欠です.
- ダイラック点の近くのグラフェンのユニークな電子特性には,重要な研究関心があります.
- 非局所輸送の理解は,新しい電子行動の探索の鍵です.
研究 の 目的:
- ホールバー幾何学を用いてグラフェンの非局所輸送現象を調査する.
- 低磁場下におけるディラック点近くの非局所反応を特徴づけるために.
- この非局所的効果の温度依存性を探求するために.
主な方法:
- ホールバーの構成で非ローカル輸送測定を行った.
- 直接電荷の流れ経路から遠くに位置した電圧探査機を使用した.
- 磁場は0.1テスラ以下で,温度も様々だった.
主要な成果:
- ダイラック点の近くで,実質的な非局所反応が観察されました.
- この反応は室温まで持続した.
- 非局所性は,スピン/バレーの変性解除による長距離の味の流れと一致していました.
結論:
- 非局所輸送測定は,グラフェンの主要な電子現象を明らかにします.
- スピン/渓谷電流によって引き起こされる観測された効果は,中立点の近くで有意である.
- この発見は,グラフェンにおける磁気輸送の理解に影響を及ぼすことが期待されています.
関連する概念動画
01:16Second Uniqueness Theorem
Consider a region consisting of several individual conductors with a definite charge density in the region between these conductors. The second uniqueness theorem states that if the total charge on each conductor and the charge density in the in-between region are known, then the electric field can be uniquely determined.
In contrast, consider that the electric field is non-unique and apply Gauss's law in divergence form in the region between the conductors and the integral form to the surface...
In contrast, consider that the electric field is non-unique and apply Gauss's law in divergence form in the region between the conductors and the integral form to the surface...
02:32The de Broglie Wavelength
In the macroscopic world, objects that are large enough to be seen by the naked eye follow the rules of classical physics. A billiard ball moving on a table will behave like a particle; it will continue traveling in a straight line unless it collides with another ball, or it is acted on by some other force, such as friction. The ball has a well-defined position and velocity or well-defined momentum, p = mv, which is defined by mass m and velocity v at any given moment. This is the typical...
01:26Electric Field at the Surface of a Conductor
Consider a conductor in electrostatic equilibrium. The net electric field inside a conductor vanishes, and extra charges on the conductor reside on its outer surface, regardless of where they originate.
In the 19th century, Michael Faraday conducted the famous ice pail experiment to prove that the charges always reside on the surface of a conductor. The experimental set-up consists of a conducting uncharged container mounted on an insulating stand. The outer surface of the container is...
In the 19th century, Michael Faraday conducted the famous ice pail experiment to prove that the charges always reside on the surface of a conductor. The experimental set-up consists of a conducting uncharged container mounted on an insulating stand. The outer surface of the container is...
01:30Electric Field of Two Equal and Opposite Charges
Atoms generally contain the same number of positively and negatively charged particles, protons, and electrons. Hence, they are electrically neutral. However, the centers of the positive and negative charges do not always coincide. In such a scenario, the electric field of an atom may not be zero.
A separation of the positive and negative charges can lead to a weak, remnant effect of the positive and negative charges. The expectation is that the more the distance between the positive and...
A separation of the positive and negative charges can lead to a weak, remnant effect of the positive and negative charges. The expectation is that the more the distance between the positive and...
01:25Electric Field Lines
The three-dimensional representation of the electric field of a positive point charge requires tracing the electric field vectors, whose lengths decrease as the square of their distance from the charge and which point away from the charge at each point. This vector field is no doubt challenging to visualize. The visualization of electric fields becomes quickly intractable as the number of charges increases.
The solution to this problem is to use electric field lines, which are not vectors but...
The solution to this problem is to use electric field lines, which are not vectors but...
01:28Debye–Huckel–Onsager Conductance Equation
The Debye-Hückel-Onsager equation is a cornerstone of physical chemistry, providing a method to determine the molar conductance (Λm) and molar conductance at infinite dilution (Λ°m) for uni-univalent electrolytes.Uni-univalent electrolytes are electrolytes that dissociate in solution to produce one cation with a +1 charge and one anion with a –1 charge per formula unit.This equation addresses two crucial phenomena: the asymmetry effect and the electrophoretic effect. According to this equation,...