相关实验视频
Updated: Jul 26, 2026

11:21
Cooling an Optically Trapped Ultracold Fermi Gas by Periodical Driving
Published on: March 30, 2017
不相称的量子晶体的热力学
P W Anderson1, W F Brinkman, David A Huse
1Department of Physics, Princeton University, Princeton, NJ 08544, USA.
概括
我们开发了一种量子固体理论,解释了空位度随温度的变化. 这种热力学模型与实验中发现的固体-4相一致,特别是在超固体性方面.
科学领域:
- 热力学是一种热力学.
- 量子物理学的量子物理学
- 凝聚物质物理学 凝聚物质物理学
背景情况:
- 量子固体表现出独特的热力学特性,由于量子效应,如零点空位.
- 了解这些特性对于解释诸如固体-4等材料中的超固体性等现象至关重要.
研究的目的:
- 为不相称量子固体的热力学开发一个理论框架.
- 解释这些固体中空位度和比热的温度依赖性.
- 提供对超固体实验观测的见解.
主要方法:
- 一个不相称的量子固体的基本状态的理论建模.
- 对量子零点空缺和间隙的分析.
- 导出热力学性质的温度依赖关系.
主要成果:
- 预计净空置度在低温下变化为T^4.
- 由于空位导致的比热的第一次校正被证明是T^7.7的变化.
- 理论预测与实验数据对固体-4的良好一致.
结论:
- 提出的理论成功地解释了不相称的量子固体的热力学行为.
- 这些发现支持对包括超固体在内的固体-4实验结果的解释.
- 这项工作鼓励对量子晶体及其独特特性进行进一步的研究.
相关概念视频
Phase Transitions: Melting and Freezing
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...
Third Law of Thermodynamics
A pure, perfectly crystalline solid possessing no kinetic energy (that is, at a temperature of absolute zero, 0 K) may be described by a single microstate, as its purity, perfect crystallinity,and complete lack of motion means there is but one possible location for each identical atom or molecule comprising the crystal (W = 1). According to the Boltzmann equation, the entropy of this system is zero.
Entropy and the Second Law of Thermodynamics
The second law of thermodynamics can be stated quantitatively using the concept of entropy. Entropy is the measure of disorder of the system.
The relation between entropy and disorder can be illustrated with the example of the phase change of ice to water. In ice, the molecules are located at specific sites giving a solid state, whereas, in a liquid form, these molecules are much freer to move. The molecular arrangement has therefore become more randomized. Although the change in average...
The relation between entropy and disorder can be illustrated with the example of the phase change of ice to water. In ice, the molecules are located at specific sites giving a solid state, whereas, in a liquid form, these molecules are much freer to move. The molecular arrangement has therefore become more randomized. Although the change in average...
Theory of Metallic Conduction
The conduction of free electrons inside a conductor is best described by quantum mechanics. However, a classical model makes predictions close to the results of quantum mechanics. It is called the theory of metallic conduction.
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...
Entropy and the Second Law of Thermodynamics
Consider an isolated system in which a hot object is placed in contact with a cold one. This is an irreversible process that eventually leads both objects to reach the same equilibrium temperature. It is crucial to note that the constituents of any substance exhibit increased disorder at higher temperatures. As a cold substance absorbs heat, its constituents become more disordered. The energy transfer from a hotter object to a cooler one increases the system's disorder or randomness. This...
Absolute Entropies and the Third Law of Thermodynamics
Ludwig Edward Boltzmann developed a definition for entropy, which stated that absolute entropy is proportional to the natural logarithm of the number of possible combinations of particles. Entropy stands alone among state functions as the only one whose absolute values can be determined.Consider a gas sample confined to a container. As the container expands, the energy levels of gas molecules become more closely spaced. This increases the number of available energy states, thereby increasing...

