関連する実験動画
Updated: May 22, 2026

11:21
Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving
Published on: March 30, 2017
量子ガスのロトン型モード軟化には,空洞媒介による長距離相互作用がある
R Mottl1, F Brennecke, K Baumann
1Institute for Quantum Electronics, ETH Zürich, Zürich, Switzerland.
まとめ
研究者は,遠距離相互作用を持つ量子ガスを研究し,ロトンのような刺激と超流体から超固体への移行を観察しました. この研究は,複雑な多体系システムの量子シミュレーションを進めている.
科学分野:
- 量子物理学とは,量子物理学のことです.
- 凝縮物質物理学 凝縮物質物理学
- 原子物理学 原子物理学とは
背景:
- 量子ガスの長距離相互作用は,超流体ヘリウムに類似した,ロートンのような興奮スペクトルにつながる可能性があります.
- ボーゼ-アインシュタイン凝縮体 (BECs) は,量子現象を研究するためのプラットフォームを提供します.
- 孔間間介相互作用は,BECにおける粒子間の力を制御することを可能にします.
研究 の 目的:
- ボーゼ-アインシュタイン凝縮物の刺激スペクトルと空洞媒介の長距離相互作用を調査する.
- 相互作用の強さを増加させることで,刺激モードや相変化に及ぼす影響を調べる.
- ロートン型の興奮と超流体から超固体への移行の理論的予測を実験的に検証する.
主な方法:
- ボーゼ-アインシュタイン凝縮液を用いて,空洞媒介相互作用を行いました.
- 刺激スペクトルを探査するために,ブラッグ光譜学の変種を使用しました.
- 理論的な比較のために,ab initio計算を行いました.
主要な成果:
- 相互作用の強度が増加する限りのモメンタムで,刺激モードの柔らかくなることが観察される.
- 超流体から超固体への相変化を特定しました.
- 実験結果は,理論的な計算と非常に一致していました.
- 段階移行時に異なる感受性を検出した.
結論:
- この研究では,長距離相互作用するボゼ・アインシュタイン凝縮物の興奮スペクトルを成功裏に特徴付けました.
- ロトンのような特徴の出現と,超流体から超固体への移行を実証した.
- この発見は,多体物理学の量子シミュレーションのためにそのようなシステムの使用を支持する.
関連する概念動画
Standing Waves in a Cavity
A household microwave and lasers are examples of standing electromagnetic waves in a cavity. When two conducting metal plates are placed parallel at the nodal planes, it creates a cavity where standing waves are formed. The cavity between the two planes is analogous to a stretched string held at the points x = 0 and x = L. Here, the distance 'L' between the two planes must be an integer multiple of half of the wavelength. The wavelengths that satisfy this condition are given by:
The Quantum-Mechanical Model of an Atom
Shortly after de Broglie published his ideas that the electron in a hydrogen atom could be better thought of as being a circular standing wave instead of a particle moving in quantized circular orbits, Erwin Schrödinger extended de Broglie’s work by deriving what is now known as the Schrödinger equation. When Schrödinger applied his equation to hydrogen-like atoms, he was able to reproduce Bohr’s expression for the energy and, thus, the Rydberg formula governing hydrogen spectra. Schrödinger...
The 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...
¹H NMR: Long-Range Coupling
The coupling interactions of nuclei across four or more bonds are usually weak, with J values less than 1 Hz. While these are usually not observed in spectra, the presence of multiple bonds along the coupling pathway can result in observable long-range coupling.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene π orbitals.
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene π orbitals.
Hybridization of Atomic Orbitals II
sp3d and sp3d 2 Hybridization
Atomic Nuclei: Types of Nuclear Relaxation
Nuclear relaxation restores the equilibrium population imbalance and can occur via spin–lattice or spin–spin mechanisms, which are first-order exponential decay processes.
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers energy to a nearby...
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers energy to a nearby...
