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Corriente de espín de magnones antiferromagnéticos generados en sub-terahertz
Junxue Li1, C Blake Wilson2,3, Ran Cheng1,4
1Department of Physics and Astronomy, University of California, Riverside, CA, USA.
Nature
|January 29, 2020
Resumen
Los investigadores demostraron el bombeo de espín sub-terahertz en las heteroestructuras antiferromagnéticas. Este trabajo muestra la generación y detección eléctrica de corrientes de espín puras a partir de la resonancia antiferromagnética, allanando el camino para dispositivos espintrónicos ultrarrápidos.
Área de la Ciencia:
- Física de la materia condensada
- La tecnología Spintronics
- Ciencias de los materiales
Sus antecedentes:
- Los antiferromagnetos ofrecen una dinámica de giro más rápida que los ferromagnetos para dispositivos ultrarrápidos.
- La generación y detección eléctrica de corrientes de espín en antiferromagnetos sigue siendo un desafío.
Objetivo del estudio:
- Demostrar el bombeo de espín subterahertz y la detección eléctrica de corrientes de espín puras en heteroestructuras antiferromagnéticas.
- Para investigar la excitación de magnon y la conversión de carga de espín en antiferromagnetos a altas frecuencias.
Principales métodos:
- Fabricación de heteroestructuras con Cr2O3 antiferromagnético uniaxial y metales pesados (Pt, β-Ta).
- Excitación de la resonancia antiferromagnética (AFMR) a 0,240 THz y 2,7 T, y una segunda resonancia a 10,5 T.
- Detección eléctrica de corrientes de espín generadas a través del efecto Hall de espín inverso.
Principales resultados:
- Generación y detección exitosas de corrientes de espín puras tanto de AFMR como de una segunda resonancia en heteroestructuras de Cr2O3/metal pesado.
- Confirmación inequívoca de las corrientes de espín puras mediante la inversión de la polaridad del voltaje al cambiar el detector de metal (Pt/Ta) o la dirección del campo magnético.
- Las mediciones de la dependencia de la temperatura y el efecto Seebeck de espín indican contribuciones de magnon coherentes e incoherentes a la corriente de espín.
Conclusiones:
- Este estudio demuestra explícitamente el bombeo de espín subterahertz y la detección eléctrica de corrientes de espín puras en antiferromagnetos.
- Los hallazgos destacan las características únicas de excitación de magnon y su papel en la conversión de carga de espín a altas frecuencias.
- Los resultados abren nuevas vías para el desarrollo de dispositivos espintrónicos ultrarrápidos basados en materiales antiferromagnéticos.
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