Video Experimental Relacionado
Updated: Apr 13, 2026
15:58
Measurement of Coherence Decay in GaMnAs Using Femtosecond Four-wave Mixing
Published on: December 3, 2013
6.2K
La velocidad máxima de conmutación magnética en los medios de grabación granulares
I Tudosa1, C Stamm, A B Kashuba
1Stanford Synchrotron Radiation Laboratory, PO Box 20450, Stanford, California 94309, USA.
Nature
|April 23, 2004
Resumen
Los investigadores descubrieron que los pulsos de campo magnético extremadamente cortos y de alta intensidad interrumpen el registro magnético determinista. Este fenómeno, causado por una pérdida temporal del orden ferromagnético, establece un límite fundamental en la velocidad de almacenamiento de datos magnéticos.
Área de la Ciencia:
- Física Física es la física de las cosas.
- Ciencia de los materiales Ciencia de los materiales.
- Ingeniería Eléctrica Ingeniería Eléctrica.
Sus antecedentes:
- Los dispositivos de memoria magnética almacenan datos mediante el control de la magnetización.
- La conmutación precesiva es el método más rápido para la grabación magnética.
- La grabación más rápida requiere tiempos de conmutación más cortos, logrados aumentando la amplitud de pulso de escritura.
Objetivo del estudio:
- Para investigar los efectos de los pulsos de campos magnéticos extremos en la conmutación de precesión.
- Para determinar si el aumento de la amplitud del pulso de escritura acorta indefinidamente el tiempo de conmutación.
- Para identificar los límites finales de la velocidad de grabación magnética determinista.
Principales métodos:
- Aplicación de pulsos muy cortos de campos magnéticos muy altos a medios magnéticos.
- Observación y análisis del comportamiento de conmutación de la magnetización en condiciones extremas.
Principales resultados:
- La conmutación precesiva se vuelve no determinista bajo condiciones de pulso extremas.
- La conmutación ocurre al azar a través de una amplia gama de campos magnéticos.
- Se observa un colapso momentáneo del orden ferromagnético.
Conclusiones:
- La grabación magnética determinista tiene un límite de velocidad final.
- Los pulsos extremos del campo magnético interrumpen la naturaleza predecible de la conmutación de precesión.
- Comprender este límite es crucial para el avance de la tecnología de memoria magnética.
Videos de Conceptos Relacionados
01:14Atomic Nuclei: Nuclear Spin State Population Distribution
2.6K
Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.
2.6K
01:23Atomic Nuclei: Nuclear Relaxation Processes
1.4K
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis, the precessing magnetic moments are randomly oriented around the z-axis.
1.4K
01:28Types Of Superconductors
1.9K
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...
1.9K
01:30Propagation Speed of Electromagnetic Waves
5.0K
Electromagnetic waves are consistent with Ampere's law. Assuming there is no conduction current Ampere's law is given as:
5.0K
01:23Magnetic Field due to Moving Charges
12.5K
A stationary charge creates and interacts with the electric field, while a moving charge creates a magnetic field.
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
12.5K
01:31Ferromagnetism
3.6K
Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...
3.6K