对音声四极拓绝缘体的观察
Marc Serra-Garcia1, Valerio Peri1, Roman Süsstrunk1
1Institute for Theoretical Physics, ETH Zurich, 8093 Zürich, Switzerland.
Nature
|January 16, 2018
概括
研究人员通过实验观察了一种音声四极拓绝缘体,这是一种呈现独特边缘和角状态的新材料. 这一发现促进了对拓超材料的理解和设计,用于未来的波导应用.
科学领域:
- 凝聚物质物理学
- 拓材料科学
- 超材料工程
背景情况:
- 固体中的现代电荷极化理论概括了贝里相,这对于拓带结构至关重要.
- 量子极化理论延伸到更高的多极时刻,预测四极拓绝缘体.
- 理论上,二维四极绝缘器具有间隙边缘模式和零维角状态.
研究的目的:
- 通过实验观察和描述一个音声四极拓绝缘体.
- 验证机械元材料中空隙边缘和内空角状态的理论预测.
- 探索拓角状态的潜力,以进行先进的元材料设计.
主要方法:
- 在机械超材料中体积,边缘和角物理的实验性表征.
- 通过四极理论预测的拓和非拓相的比较分析.
- 测量机械性能以确认拓特性.
主要成果:
- 语音四极拓绝缘体的实验观测和描述.
- 证实边缘间隙状态和零维内角状态.
- 通过比较拓和非拓阶段来验证理论预测.
结论:
- 这项研究报告了第一个音声四极拓绝缘体的实验实现.
- 观察到的拓角状态是创建拓保护波导的重要进展.
- 这项工作为设计具有量身定制的拓性质的先进超材料开辟了新的途径.
相关概念视频
Conductors and Insulators
11.0K
Some materials may easily let electrical charges pass through them, while others obstruct their flow. The former are called conductors and the latter insulators. The atomic structures of materials determine whether they are conductors or insulators of electricity.
Most metals are conductors. Their atomic configuration is such that one or more electron(s) are loosely bound to the nucleus in each atom. Thus, a sea of mobile electrons are available in them, known as free electrons. Their easy...
Most metals are conductors. Their atomic configuration is such that one or more electron(s) are loosely bound to the nucleus in each atom. Thus, a sea of mobile electrons are available in them, known as free electrons. Their easy...
11.0K
Insulation Coordination
583
Insulation coordination is the process of matching electric equipment's insulation strength with protective device characteristics to protect the equipment against expected overvoltages. This selection is based on engineering judgment and cost. Equipment can generally withstand short-duration high transient overvoltages, but repeated tests with identical waveforms can yield inconsistent results. As a result, standard impulse voltage waveforms are used for testing, defined by specific times...
583
Thermal Insulation in Masonry Walls
572
In hot, dry climates, the thermal mass of masonry walls can be beneficial, absorbing heat during the day and releasing it at night, thereby stabilizing indoor temperatures. However, in most other climates, additional insulation is necessary to enhance thermal resistance.
External insulation can be applied using an Exterior Insulation and Finish System (EIFS), which involves affixing panels of plastic foam to the wall and covering them with a polymeric stucco reinforced with glass fiber mesh....
External insulation can be applied using an Exterior Insulation and Finish System (EIFS), which involves affixing panels of plastic foam to the wall and covering them with a polymeric stucco reinforced with glass fiber mesh....
572
Naturalistic Observations
17.6K
If you want to understand how behavior occurs, one of the best ways to gain information is to simply observe the behavior in its natural context. However, people might change their behavior in unexpected ways if they know they are being observed. How do researchers obtain accurate information when people tend to hide their natural behavior? As an example, imagine that your professor asks everyone in your class to raise their hand if they always wash their hands after using the restroom. Chances...
17.6K
Observational Learning
1.0K
Albert Bandura's observational learning, also known as imitation or modeling, occurs when a person observes and imitates another's behavior. It is a quicker process than operant conditioning. A well-known example is the Bobo doll study, where children who saw an adult acting aggressively towards the doll were more likely to act aggressively when left alone, compared to those who observed a nonaggressive adult. Many psychologists view observational learning as a form of latent learning...
1.0K
Observational Studies
11.2K
Observational studies are a type of analytical study where researchers observe events without any interventions. In other words, the researcher does not influence the response variable or the experiment's outcome.
There are three types of observational studies – Prospective, retrospective, and cross-sectional.
Prospective Study
Prospective studies, also known as longitudinal or cohort studies, are carried out by collecting future data from groups sharing similar characteristics. One...
There are three types of observational studies – Prospective, retrospective, and cross-sectional.
Prospective Study
Prospective studies, also known as longitudinal or cohort studies, are carried out by collecting future data from groups sharing similar characteristics. One...
11.2K


