相关实验视频

Updated: Jul 18, 2025

Measurement of Coherence Decay in GaMnAs Using Femtosecond Four-wave Mixing

Measurement of Coherence Decay in GaMnAs Using Femtosecond Four-wave Mixing

Published on: December 3, 2013

在Su-Schrieffer-Heeger声波格子中的反平价时间对称性

Bolun Hu^1,2, Zhiwang Zhang¹, Zichong Yue¹

¹Department of Physics, MOE Key Laboratory of Modern Acoustics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.

Physical review letters

|August 25, 2023

概括

研究人员将反平价时间 (APT) 对称性扩展到声学,使用非赫米蒂安式苏-施里弗-希格 (SSH) 格子. 这种声学平台揭示了拓缺陷状态如何依赖于非赫密斯相和对称性.

科学领域:

凝聚物质物理学凝聚物质物理学
拓学材料拓学材料
声学超材料是一种声学超材料.

背景情况:

苏 - 施里弗 - 希格尔 (SSH) 模型描述了1D系统中的拓性质,具有奇拉对称性,导致中间隙表面状态.
在非赫米特系统中,平价时间 (PT) 和反PT (APT) 对称性至关重要,使无折射传播等现象成为可能.
将这些对称度扩展到声学系统,为拓声学开辟了新的途径.

研究的目的:

在声学环境中引入和研究反平价时间对称性 (APT).
为了探索在非赫米斯式SSH网格中拓缺陷状态的行为,以收益和损失.
为了证明声学非赫密特式SSH格子在研究拓相的实用性.

主要方法:

实现一个声学Su-Schrieffer-Heeger (SSH) 格子与工程增益和损失组件.
对能量分散和拓缺陷状态的实验和理论分析.
研究不同对称相 (PT,APT,失对称) 对缺陷状态的影响.

主要成果:

在声学SSH网格中存在拓缺陷状态的证实.
内部空隙拓缺陷状态的存在和特征被证明取决于非赫米特阶段.
破碎的对称性抑制了缺陷状态,而完整的PT或APT对称性导致分别减弱或 evanescent 衰变.

结论:

非赫米蒂安式SSH网格为探索声学中的拓物理提供了一个多功能平台.
声学APT对称性成功实现,为新浪现象开辟了新的可能性.
这项研究阐明了非赫密斯相和对称性在拓缺陷状态的表现中的关键作用.

更多相关视频

Recording Spatially Restricted Oscillations in the Hippocampus of Behaving Mice

Recording Spatially Restricted Oscillations in the Hippocampus of Behaving Mice

Published on: July 1, 2018

Setting Limits on Supersymmetry Using Simplified Models

Setting Limits on Supersymmetry Using Simplified Models

Published on: November 15, 2013

相关概念视频

Properties of Fourier series II

Properties of Fourier series II

Time scaling of signals is a crucial concept in signal processing that affects the Fourier series representation without altering its coefficients. The process modifies the fundamental frequency, thereby changing how the series represents the signal over time. This principle is essential in various applications, including audio and image processing, where signal manipulation is frequent. Understanding function symmetries is fundamental to simplifying the Fourier series.
A function f(t) is...

Bewley Lattice Diagram

Bewley Lattice Diagram

The Bewley lattice diagram, developed by L. V. Bewley, effectively organizes the reflections occurring during transmission-line transients. It visually represents how voltage waves propagate and reflect within a transmission line, making it easier to understand the complex interactions that occur.

The de Broglie Wavelength

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...

Symmetry in Maxwell's Equations

Symmetry in Maxwell's Equations

Once the fields have been calculated using Maxwell's four equations, the Lorentz force equation gives the force that the fields exert on a charged particle moving with a certain velocity. The Lorentz force equation combines the force of the electric field and of the magnetic field on the moving charge. Maxwell's equations and the Lorentz force law together encompass all the laws of electricity and magnetism. The symmetry that Maxwell introduced into his mathematical framework may not be...

Interference: Path Lengths

Interference: Path Lengths

Consider two sources of sound, that may or may not be in phase, emitting waves at a single frequency, and consider the frequencies to be the same.
Two special sources may be considered when they are in phase. This can be easily achieved by feeding the two sources from the same source. An example would be synchronizing the two speakers by feeding them with the same source, such as the sound waves produced by a tuning fork. This setup ensures that the two sources have the same frequency and are...

Sound Waves: Interference

Sound Waves: Interference

Sound waves can be modeled either as longitudinal waves, wherein the molecules of the medium oscillate around an equilibrium position, or as pressure waves. When two identical waves from the same source superimpose on each other, the combination of two crests or two troughs results in amplitude reinforcement known as constructive interference. If two identical waves, that are initially in phase, become out of phase because of different path lengths, the combination of crests with troughs...