由量子几何学实现的迪拉克平带超导的证据
Haidong Tian1, Xueshi Gao1, Yuxin Zhang1
1Department of Physics, The Ohio State University, Columbus, OH, USA.
Nature
|February 15, 2023
概括
在扭曲的双层石墨烯中探索了平面带的超导性,揭示了新的临界电流机制和强的超导性. 这挑战了传统理论,表明超流体刚性是由相互作用驱动的,而不是动能主导的.
科学领域:
- 凝聚物质物理学
- 超导性
- 材料科学
背景情况:
- 平带超导体表现出极其缓慢的电荷载体速度,这对传统的巴丁-库珀-施里弗理论构成悖论.
- 了解这些系统中的超导性对于解开高温超导体和重系统的奥秘至关重要.
研究的目的:
- 研究超导狄拉克平带系统中极小速度的影响.
- 探索双层扭曲石墨烯的超导性及其相关性质的出现.
主要方法:
- 使用了Schwinger限制的非线性运输研究.
- 在特定的莫雷超级晶格填充分数范围内研究了双层扭曲石墨烯.
- 测量了超流体刚度和超导过渡温度.
主要成果:
- 演示了极其缓慢的正常状态漂移速度 (约. 1000 m/s) 的时间.
- 在超导状态下确定了一个新的临界电流限制机制,类似于相对论超流体.
- 观察到的超流体刚度主要是由超导间隙,而不是动能,表明量子几何贡献.
- 发现了小型库珀对和超导过渡温度与费米温度比的证据,
结论:
- 这项研究提供了关于平带系统中非传统超导的见解,挑战了现有的理论.
- 这些发现突显了量子几何和强相互作用在驱动超导性的作用.
- 在扭曲的双层石墨烯中观察到的现象为探索奇特的超导状态提供了一个新的平台.
相关概念视频
Theory of Metallic Conduction
1.4K
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,...
1.4K
The de Broglie Wavelength
26.0K
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...
26.0K
Superconductor
1.2K
A substance that reaches superconductivity, a state in which magnetic fields cannot penetrate, and there is no electrical resistance, is referred to as a superconductor. In 1911, Heike Kamerlingh Onnes of Leiden University, a Dutch physicist, observed a relation between the temperature and the resistance of the element mercury. The mercury sample was then cooled in liquid helium to study the linear dependence of resistance on temperature. It was observed that, as the temperature decreased, the...
1.2K
The Pauli Exclusion Principle
42.7K
The arrangement of electrons in the orbitals of an atom is called its electron configuration. We describe an electron configuration with a symbol that contains three pieces of information:
42.7K
Band Theory
15.3K
When two or more atoms come together to form a molecule, their atomic orbitals combine and molecular orbitals of distinct energies result. In a solid, there are a large number of atoms, and therefore a large number of atomic orbitals that may be combined into molecular orbitals. These groups of molecular orbitals are so closely placed together to form continuous regions of energies, known as the bands.
The energy difference between these bands is known as the band gap.
Conductor, Semiconductor,...
The energy difference between these bands is known as the band gap.
Conductor, Semiconductor,...
15.3K
Electric Field at the Surface of a Conductor
4.7K
Consider a conductor in electrostatic equilibrium. The net electric field inside a conductor vanishes, and extra charges on the conductor reside on its outer surface, regardless of where they originate.
In the 19th century, Michael Faraday conducted the famous ice pail experiment to prove that the charges always reside on the surface of a conductor. The experimental set-up consists of a conducting uncharged container mounted on an insulating stand. The outer surface of the container is...
In the 19th century, Michael Faraday conducted the famous ice pail experiment to prove that the charges always reside on the surface of a conductor. The experimental set-up consists of a conducting uncharged container mounted on an insulating stand. The outer surface of the container is...
4.7K


