异常的结的 evanescent 语音子
Yi Chen1,2, Jonathan L G Schneider3, Ke Wang3,4
1Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany. yi.chen@partner.kit.edu.
Nature communications
|October 25, 2024
概括
我们引入了结的 evanescent 波,这些波在弹性元材料中表现出很大的空间衰变长度. 这些波违反了圣维纳特原理,使其在远程机械传感中具有潜在的应用.
科学领域:
- 物理 物理学 物理
- 材料科学 材料科学 材料科学
- 固体力学 固体力学是什么
背景情况:
- 发光波在波浪现象中无处不在,其特点是空间衰变.
- 这些波通常以有限的频率进行研究,在时间和空间中表现出振荡.
- 在零频率下, evanescent 波是消失的.
- 结,结,结,结,结,结,结,结,结,结,结,结,结,结,结,结,结,结,结,结,结,结,结,结,结,结,结,结,结,结,结,结,结,结
- 随着时间的推移,导致静态解决方案.
研究的目的:
- 介绍并定义"结的 evanescent 波"作为在零固有频率的 eigensolutions.
- 调查带结构最小值和结的 evanescent 声子之间的联系.
- 探索在静态弹性中设计大衰变长度的潜力.
主要方法:
- 在零固有频率下分析布洛赫周期问题.
- 在复杂平面中利用考希-里曼方程,将带结构最小值与结的 evanescent 声子联系起来.
- 将理论分析与实验验证相结合,用于有限大小的样本.
主要成果:
- 结的 evanescent 波被确定为 Bloch 周期问题的静态自身解决方案.
- 在带结构最小和结的 evanescent phonons之间建立了直接的联系.
- 当带最小接近零时 (软模式) 实现了异常大的指数衰减长度.
- 由于这些波的线性组合,在有限大小的样本中观察到干扰效应.
结论:
- 结的 evanescent 波提供了一个机制,在静态弹性中设计大型特征性衰变长度.
- 这些波的违反圣维纳特原理为远程机械传感开辟了可能性.
- 理论和实验结果显示出极好的一致性,验证了这些发现.
相关概念视频
02:39Phase Transitions: Melting and Freezing
12.3K
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...
12.3K
02:31Phase Transitions
19.0K
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...
19.0K
02:39Phase Transitions: Vaporization and Condensation
17.4K
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...
17.4K
01:29Potential Due to a Polarized Object
367
A neutral atom consists of a positively charged nucleus surrounded by a negatively charged electron cloud. When placed in an external electric field, the external electric force pulls the electrons and nucleus apart, opposite to the intrinsic attraction between the nucleus and the electrons. The opposing forces balance each other with a slight shift between the center of masses of the nucleus and the electron cloud, resulting in a polarized atom. On the other hand, a few molecules, like water,...
367
02:54Molecular and Ionic Solids
17.0K
Crystalline solids are divided into four types: molecular, ionic, metallic, and covalent network based on the type of constituent units and their interparticle interactions.
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
17.0K
02:33Phase Transitions: Sublimation and Deposition
16.9K
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...
16.9K