Video Experimental Relacionado
Updated: Aug 9, 2025
05:39
Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
9.7K
La evidencia de la superconductividad de banda plana de Dirac habilitada por la geometría cuántica
Haidong Tian1, Xueshi Gao1, Yuxin Zhang1
1Department of Physics, The Ohio State University, Columbus, OH, USA.
Nature
|February 15, 2023
Resumen
La superconductividad en bandas planas se explora en grafeno de doble capa retorcida, revelando un nuevo mecanismo de corriente crítica y una fuerte superconductividad de acoplamiento. Esto desafía las teorías convencionales al mostrar que la rigidez superfluida está impulsada por la interacción, no dominada por la energía cinética.
Área de la Ciencia:
- Física de la materia condensada
- Superconductividad
- Ciencias de los materiales
Sus antecedentes:
- Los superconductores de banda plana exhiben velocidades de carga extremadamente lentas, lo que plantea una paradoja para la teoría convencional de Bardeen-Cooper-Schrieffer.
- Comprender la superconductividad en estos sistemas es crucial para desentrañar los misterios en los superconductores de alta temperatura y los sistemas de fermiones pesados.
Objetivo del estudio:
- Para investigar el impacto de velocidades muy pequeñas en sistemas de banda plana de Dirac superconductores.
- Explorar el surgimiento de la superconductividad y sus propiedades asociadas en el grafeno de doble capa retorcida.
Principales métodos:
- Se utilizaron estudios de transporte no lineal limitados por Schwinger.
- El grafeno de doble capa retorcida investigado en un rango específico de fracción de relleno de superred de moiré.
- La rigidez superfluida medida y la temperatura de transición superconductora.
Principales resultados:
- Se ha demostrado una velocidad de deriva en estado normal extremadamente lenta (aprox. 1000 m/s) para el transporte de mercancías.
- Identificó un nuevo mecanismo limitante para la corriente crítica en el estado superconductor, análogo a los superfluidos relativistas.
- La rigidez superfluida observada dominada por la brecha superconductora, no la energía cinética, indica una contribución geométrica cuántica.
- Encontró evidencia de pequeños pares de Cooper y una temperatura de transición superconductora a la relación de temperatura de Fermi que excede la unidad, lo que sugiere una superconductividad de acoplamiento ultra fuerte.
Conclusiones:
- El estudio proporciona información sobre la superconductividad no convencional en sistemas de banda plana, desafiando las teorías existentes.
- Los hallazgos destacan el papel de la geometría cuántica y las fuertes interacciones en la conducción de la superconductividad.
- Los fenómenos observados en el grafeno de doble capa retorcida ofrecen una nueva plataforma para explorar estados superconductores exóticos.
Videos de Conceptos Relacionados
01:17Theory 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
02:32The 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
01:24Superconductor
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
03:06The 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
02:35Band 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
01:26Electric 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