在无序超导体中超导体-绝缘体过渡的性质
Yonatan Dubi1, Yigal Meir, Yshai Avishai
1Department of Physics, Ben Gurion University, Beer Sheva 84105, Israel.
Nature
|October 19, 2007
概括
超导体中的混乱会产生超导体岛屿. 磁场的增加可以导致绝缘状态,但超导岛屿仍然存在,解释了像大磁阻峰这样的现象.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学是一种材料科学.
背景情况:
- 障碍通常会增加电阻,与超导的零电阻状态形成鲜明对比.
- 实验表明,在薄膜中,随着混乱或磁场的增加,超导向向绝缘过渡发生.
- 高过渡温度 (高T) 超导体本质上是无序的,这使得这种过渡至关重要.
研究的目的:
- 通过使用数值模拟来研究2D无序超导体中的超导体-绝缘体过渡.
- 了解热相波动和混乱在这种过渡中的作用.
- 解释实验观测,如磁阻峰和伪间隙现象.
主要方法:
- 2D无序超导体的数值模拟.
- 微观描述,包括热相波动.
- 分析超导顺序参数的振幅和相位相关性.
主要成果:
- 混乱会诱导高超导秩序的区域 (岛屿).
- 在弱无序状态下,磁场会抑制顺序参数振幅,导致隔离.
- 在强烈混乱的情况下,磁场会破坏岛屿之间的相相关性,导致不同的过渡.
- 超导岛在高度混乱的情况下,即使处于绝缘状态,也会保持.
结论:
- 这项研究阐明了基于障碍级别的超导体-绝缘体过渡的两个不同的机制.
- 超导岛在绝缘阶段的持久性解释了观察到的磁阻峰值.
- 这些发现提供了对低剂量的高T (c) 超导体中伪间隙现象的见解.
更多相关视频
04:51Comparison of Two Different Synthesis Methods of Single Crystals of Superconducting Uranium Ditelluride
Published on: July 8, 2021
09:06Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
Published on: March 24, 2019
相关概念视频
Types Of Superconductors
A superconductor is a substance that offers zero resistance to the electric current when it drops below a critical temperature. Zero resistance is not the only interesting phenomenon as materials reach their transition temperatures. A second effect is the exclusion of magnetic fields. This is known as the Meissner effect. A light, permanent magnet placed over a superconducting sample will levitate in a stable position above the superconductor. High-speed trains that levitate on strong...
Superconductor
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...
Semiconductors
There is variation in the electrical conductivity of materials - metals, semiconductors, and insulators that are showcased with the help of the energy band diagrams.
Metals such as copper (Cu), zinc (Zn), or lead (Pb) have low resistivity and feature conduction bands that are either not fully occupied or overlap with the valence band, making a bandgap non-existent. This allows electrons in the highest energy levels of the valence band to easily transition to the conduction band upon gaining...
Metals such as copper (Cu), zinc (Zn), or lead (Pb) have low resistivity and feature conduction bands that are either not fully occupied or overlap with the valence band, making a bandgap non-existent. This allows electrons in the highest energy levels of the valence band to easily transition to the conduction band upon gaining...
Fermi Level
The Fermi-Dirac function is represented by an S-shaped curve indicating the probability of an energy state being occupied by an electron at a given temperature. The Fermi level is the energy level at which there is a fifty percent chance of finding an electron, and it is positioned between the lower-energy valence band and the higher-energy conduction band.
At absolute zero temperature, electrons fill all energy states up to the Fermi level, leaving upper states empty. As the temperature rises,...
At absolute zero temperature, electrons fill all energy states up to the Fermi level, leaving upper states empty. As the temperature rises,...
Types of Semiconductors
Intrinsic semiconductors are highly pure materials with no impurities. At absolute zero, these semiconductors behave as perfect insulators because all the valence electrons are bound, and the conduction band is empty, disallowing electrical conduction. The Fermi level is a concept used to describe the probability of occupancy of energy levels by electrons at thermal equilibrium. In intrinsic semiconductors, the Fermi level is positioned at the midpoint of the energy gap at absolute zero. When...
Intrinsically Disordered Proteins
Intrinsically disordered proteins are a group of proteins that do not fold into specific three-dimensional structures. Their structural flexibility allows them to complement ordered proteins to perform functions that are inaccessible to rigid structures. They are more common in eukaryotes than prokaryotes and may either be exclusively intrinsically disordered or hybrid proteins, consisting of a mix of ordered and disordered regions. The absence of a rigid structure in these proteins can be...
