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Updated: Sep 10, 2025
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Measurement of Coherence Decay in GaMnAs Using Femtosecond Four-wave Mixing
Published on: December 3, 2013
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Mapeo de la deslocalización de las bandas de impureza a través de la transición arquetípica de Mott-Anderson
M Parzer1, F Garmroudi2, A Riss1
1Technische Universität Wien, Institute of Solid State Physics, 1040 Vienna, Austria.
Physical review letters
|August 27, 2025
Resumen
Los investigadores ajustaron el transporte de carga en los compuestos Fe-V-Al Heusler ajustando el contenido de hierro. Observaron una transición de estados electrónicos localizados a deslocalizados, logrando una resistividad independiente de la temperatura para aplicaciones electrónicas.
Área de la Ciencia:
- Física de la materia condensada
- Ciencias de los materiales
- Química del estado sólido
Sus antecedentes:
- El control del transporte de carga en los sólidos es vital para la electrónica.
- Las impurezas y el desorden a menudo impiden una conducción coherente.
Objetivo del estudio:
- Para controlar la formación de bandas electrónicas de los estados de impureza.
- Para investigar la localización y deslocalización del portador de carga en los compuestos Fe-V-Al Heusler.
Principales métodos:
- Cálculos de la teoría de la densidad funcional (DFT).
- Mediciones de la resistividad térmica y eléctrica específica.
- Mediciones termoeléctricas.
Principales resultados:
- La reducción del contenido de hierro controla la acumulación de banda de los estados de impureza.
- Localización de Anderson observada en concentraciones bajas de V (0< x< 0, 1).
- La transición de Mott-Anderson se observa con el aumento de la concentración de V, formando bordes de movilidad.
- La deslocalización en V3Al conduce a una resistividad independiente de la temperatura de hasta 700 K, alcanzando el límite de Mott-Ioffe-Regel.
Conclusiones:
- La estructura de la banda electrónica y el transporte de carga se pueden adaptar mediante cambios de composición en los compuestos Fe-V-Al.
- La transición de Mott-Anderson rige el cambio de estados localizados a deslocalizados.
- La resistividad independiente de la temperatura alcanzada ofrece el potencial para aplicaciones de dispositivos electrónicos estables.
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