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Tracción de Fizeau eficiente de los electrones de Dirac en el grafeno monocapa
Wenyu Zhao1, Sihan Zhao1, Hongyuan Li1,2,3
1Department of Physics, University of California, Berkeley, Berkeley, CA, USA.
Nature
|June 24, 2021
Resumen
Los científicos observaron el arrastre de Fizeau, una modificación de la velocidad de la luz en medios móviles, en el grafeno. Este efecto Doppler plasmónico muestra una mayor velocidad del polaritón plasmónico con el flujo de electrones, lo que permite el control eléctrico.
Área de la Ciencia:
- Física de la materia condensada
- La óptica cuántica
- Ciencias de los materiales
Sus antecedentes:
- El experimento de Fizeau de 1850 demostró la modificación de la velocidad de la luz en medios móviles.
- Lograr un control eficiente de la velocidad de la luz en medios electrónicos de movimiento rápido a través de la corriente eléctrica ha sido un desafío.
- El fuerte acoplamiento entre los electrones y la luz sugiere que la resistencia de Fizeau en los sistemas de flujo de electrones puede manifestarse como un efecto Doppler plasmónico.
Objetivo del estudio:
- Para observar experimentalmente el arrastre de Fizeau de los polaritones de plasmones en un medio de electrones a la deriva rápida.
- Para investigar el efecto Doppler plasmónico en el grafeno monocapa bajo un fuerte sesgo eléctrico.
- Para demostrar el control eléctrico de los polaritones plasmónicos de superficie no recíprocos.
Principales métodos:
- Se utilizó grafeno monocapa fuertemente sesgado con alta movilidad de electrones y propagación lenta de plasmones.
- Se empleó nanoscopia criogénica de campo cercano al infrarrojo para obtener imágenes de los modos de polaritón plasmónico.
- Las longitudes de onda plasmónicas desplazadas por Doppler se miden a bajas temperaturas.
Principales resultados:
- Se ha observado directamente la resistencia de Fizeau de los polaritones plasmónicos en el grafeno.
- Se ha demostrado la propagación no recíproca de plasmones debido a la rápida deriva de los electrones de Dirac.
- Se midió una diferencia de longitud de onda plasmónica de hasta el 3,6% entre los plasmones que se mueven con y contra la deriva de electrones.
Conclusiones:
- El efecto Doppler plasmónico se observó con éxito en sistemas electrónicos, específicamente en grafeno sesgado.
- Este trabajo supera los desafíos anteriores relacionados con las velocidades rápidas de los plasmones en los metales convencionales.
- Los hallazgos ofrecen vías para el control eléctrico de los polaritones plasmónicos de superficie no recíprocos en sistemas de no equilibrio.
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