量子相移行時のバーディン・クーパー・シュリッファー基本状態の分解
R Jaramillo1, Yejun Feng, J C Lang
1The James Franck Institute and Department of Physics, The University of Chicago, Chicago, Illinois 60637, USA.
Nature
|May 22, 2009
まとめ
元素クロムは反鉄磁性を巡回している. 液圧圧の適用は量子相変化を誘導し,磁性を抑制しながら電子穴相互作用を保ち,量子批判性を研究するためのモデルシステムを提供します.
科学分野:
- 固体物理学 固体物理学とは
- 量子物質は,量子的な物質である.
- 原子物理学 原子物理学とは
背景:
- 量子物質物理学の進歩は,通常と異国的な状態の間のつながりを明らかにし,しばしば量子相変化によって結びついています.
- 量子変動と相関の理解は,ゼロ温度の不安定性に近いことが重要ですが,複雑なシステムでは困難です.
- 連続的な量子相移行を証明するモデルシステムはほとんど特定されていません.
研究 の 目的:
- 元素クロムにおける水立圧下における磁力の抑制を調査する.
- 連続量子相移行と量子批判性を研究するためのモデルシステムとしてクロミウムを探求する.
- 理論的に扱える素材で,従来のオーダーとエキゾチックなオーダーの間の競争を調査する.
主な方法:
- 低温でダイアモンド・アンビル・セルを使って元素クロムに水圧圧力を加えた.
- 磁気抑制は,関連する電荷の順序を測定することによって研究されました.
- 量子変動や相変遷を検出するために直接測定を行った.
主要な成果:
- 水位圧は,バーディン・クーパー・シュリッファー (BCS) のような振る舞いを有する単純な立方金属であるクロミウムの巡回反鉄磁性を抑制する.
- 連続的な量子相移行は,波動によって引き起こされる約10GPaで発生します.
- 移行はBCSのような状態を破壊しますが,移動電子と穴の間の強い磁気相互作用を保持します.
結論:
- 元素クロムは,磁気金属における連続量子相移行を研究するためのユニークなモデルシステムとして機能します.
- この研究は,量子特異点への実験的アクセスを提供し,従来の順序とエキゾチックな順序の間の競争を調査します.
- 発見は,物質の異なる量子状態の間の基本的な関係を理解するのに寄与します.
関連する概念動画
02:31Phase Transitions
19.1K
Whether solid, liquid, or gas, a substance's state depends on the order and arrangement of its particles (atoms, molecules, or ions). Particles in the solid pack closely together, generally in a pattern. The particles vibrate about their fixed positions but do not move or squeeze past their neighbors. In liquids, although the particles are closely spaced, they are randomly arranged. The position of the particles are not fixed—that is, they are free to move past their neighbors to...
19.1K
02:39Phase Transitions: Vaporization and Condensation
16.9K
The physical form of a substance changes on changing its temperature. For example, raising the temperature of a liquid causes the liquid to vaporize (convert into vapor). The process is called vaporization—a surface phenomenon. Vaporization occurs when the thermal motion of the molecules overcome the intermolecular forces, and the molecules (at the surface) escape into the gaseous state. When a liquid vaporizes in a closed container, gas molecules cannot escape. As these gas phase...
16.9K
02:39Phase Transitions: Melting and Freezing
11.7K
Heating a crystalline solid increases the average energy of its atoms, molecules, or ions, and the solid gets hotter. At some point, the added energy becomes large enough to partially overcome the forces holding the molecules or ions of the solid in their fixed positions, and the solid begins the process of transitioning to the liquid state or melting. At this point, the temperature of the solid stops rising, despite the continual input of heat, and it remains constant until all of the solid is...
11.7K
02:33Phase Transitions: Sublimation and Deposition
16.0K
Some solids can transition directly into the gaseous state, bypassing the liquid state, via a process known as sublimation. At room temperature and standard pressure, a piece of dry ice (solid CO2) sublimes, appearing to gradually disappear without ever forming any liquid. Snow and ice sublimate at temperatures below the melting point of water, a slow process that may be accelerated by winds and the reduced atmospheric pressures at high altitudes. When solid iodine is warmed, the solid sublimes...
16.0K
01:19Phase Diagram
5.9K
The phase of a given substance depends on the pressure and temperature. Thus, plots of pressure versus temperature showing the phase in each region provide considerable insights into the thermal properties of substances. Such plots are known as phase diagrams. For instance, in the phase diagram for water (Figure 1), the solid curve boundaries between the phases indicate phase transitions (i.e., temperatures and pressures at which the phases coexist).
5.9K
01:21Phase Transitions
108
A phase transition is the process in which a substance changes from one state of matter to another, like from a solid to a liquid, liquid to gas, or vice versa, at a specific temperature and under given pressure conditions. This change is spontaneous and is affected by alterations in temperature and pressure. These parameters impact the strength of the forces between molecules (intermolecular forces) in the substance.During a phase transition, both the initial and final phases of the substance...
108