对于间隔阶段的分类兰道范式
Lakshya Bhardwaj1, Lea E Bottini1, Daniel Pajer1
1University of Oxford, Mathematical Institute, Woodstock Road, Oxford, OX2 6GG, United Kingdom.
Physical review letters
|November 1, 2024
概括
我们引入了一个统一的框架来分类具有分类对称性的间隙相,扩展兰道范式. 这种方法利用对称拓场理论来进行跨维的全面相位分类.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 量子场理论 量子场理论
- 物质的拓阶段.
背景情况:
- 具有对称性的物质的间隙相在凝聚物质中是基本的.
- 现有的分类方案可能很复杂,范围有限.
- 分类对称性为描述相位提供了更丰富的数学结构.
研究的目的:
- 开发一个统一和全面的框架来分类具有分类对称性的间隙相.
- 将兰道范式概括为包含分类对称的范式.
- 为阶段分类提供一个计算强大的方法.
主要方法:
- 提出基于对称拓场理论 (TFT) 的统一框架.
- 使用一个具有拓边界的一个维度更高的TFT.
- 以类型对称的 (1+1) 维间隙相的框架为例.
主要成果:
- 一个概括的,分类的兰道范式,用于分类间隙对称相.
- 该框架适用于任何维度.
- 对 (1+1) D 系统的方法的演示.
结论:
- 拟议的框架提供了一个简洁,全面和计算强大的方法来分类间隙对称相.
- 对称TFT为了解拓相提供了一个强大的工具.
- 该框架有可能进行更高维度的扩展和进一步的理论发展.
相关概念视频
Phase Diagrams
39.9K
A phase diagram combines plots of pressure versus temperature for the liquid-gas, solid-liquid, and solid-gas phase-transition equilibria of a substance. These diagrams indicate the physical states that exist under specific conditions of pressure and temperature and also provide the pressure dependence of the phase-transition temperatures (melting points, sublimation points, boiling points). Regions or areas labeled solid, liquid, and gas represent single phases, while lines or curves represent...
39.9K
Phase Diagram
5.8K
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).
5.8K
Phase Changes
4.2K
Phase transitions play an important theoretical and practical role in the study of heat flow. In melting or fusion, a solid turns into a liquid; the opposite process is freezing. In evaporation, a liquid turns into a gas; the opposite process is condensation.
A substance melts or freezes at a temperature called its melting point and boils or condenses at its boiling point. These temperatures depend on pressure. High pressure favors the denser form of the substance, so typically, high pressure...
A substance melts or freezes at a temperature called its melting point and boils or condenses at its boiling point. These temperatures depend on pressure. High pressure favors the denser form of the substance, so typically, high pressure...
4.2K
Phase-lead and Phase-lag Controllers
159
Understanding the working function of different types of controllers can be illustrated with practical analogies, such as adjusting a stereo's volume equalizer. Cranking up the bass involves a phase-lead controller, which functions as a high-pass filter, while increasing the treble uses a phase-lag controller, which acts as a low-pass filter. PD controllers, similar to high-pass filters, enhance the system's response to high-frequency components. PI controllers, akin to low-pass...
159
Boundary Conditions: Lossless Lines
85
Consider a single-phase, two-wire, lossless transmission line terminated by an impedance at the receiving end and a source with Thevenin voltage and impedance at the sending end. The line, with length, has a surge impedance and wave velocity determined by the line's inductance and capacitance.
At the receiving end, the boundary condition states that the voltage equals the product of the receiving-end impedance and current. This relationship is expressed as a function of the incident and...
At the receiving end, the boundary condition states that the voltage equals the product of the receiving-end impedance and current. This relationship is expressed as a function of the incident and...
85
Time and frequency -Domain Interpretation of Phase-lag Control
86
Phase-lag controllers are widely used in control systems to improve stability and reduce steady-state errors. A dimmer switch controlling the brightness of a light bulb serves as a practical example of phase-lag control, gradually adjusting the bulb's brightness. Mathematically, phase-lag control or low-pass filtering is represented when the factor 'a' is less than 1.
Phase-lag controllers do not place a pole at zero, but instead influence the steady-state error by amplifying any...
Phase-lag controllers do not place a pole at zero, but instead influence the steady-state error by amplifying any...
86


