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Efecto Nernst anómalo mejorado en el retículo de Kondo ferromagnético CeCo_{2}As_{2}

Shuyue Guan¹, Weian Guo², Pengyu Zheng²

¹Peking University, International Center for Quantum Materials, School of Physics, Beijing 100871, China.

Physical review letters

|February 6, 2026

Resumen

Los investigadores observaron un efecto Nernst anómalo (ANE) mejorado en el retículo de Kondo ferromagnético CeCo2As2. Este efecto, vinculado a la curvatura de Berry en imanes topológicos, se atribuye a bandas planas de orbitales f.

Área de la Ciencia:

Física de la Materia Condensada
Ciencia de Materiales
Materiales Cuánticos

Sus antecedentes:

El efecto Nernst anómalo (ANE) es un fenómeno termoeléctrico que genera un voltaje transversal a partir de un gradiente de temperatura en materiales magnéticos.
El ANE está fuertemente influenciado por la curvatura de Berry (BC) cerca de la energía de Fermi, particularmente en imanes topológicos.
Los retículos de Kondo, como CeCo2As2, exhiben un comportamiento electrónico complejo debido a las interacciones entre los electrones f localizados y los electrones de conducción.

Objetivo del estudio:

Investigar el efecto Nernst anómalo espontáneo en el retículo de Kondo ferromagnético CeCo2As2.
Explorar la relación entre la curvatura de Berry, las bandas planas y el ANE observado en este material.
Comprender el papel de la topología impulsada por la correlación en los sistemas de retículo de Kondo.

Principales métodos:

Medición experimental del efecto Nernst anómalo y el coeficiente Seebeck en CeCo2As2.
Análisis teórico que vincula el ANE observado con la curvatura de Berry y la estructura de bandas electrónicas.
Caracterización de las propiedades del retículo de Kondo ferromagnético de CeCo2As2.

Principales resultados:

Se observó un efecto Nernst anómalo espontáneo mejorado en CeCo2As2, que excede el coeficiente Seebeck.
El gran coeficiente Nernst anómalo se atribuye a una fuerte curvatura de Berry en bandas planas dominadas por orbitales f.
Los hallazgos sugieren la fijación de la energía de Fermi dentro de una banda plana topológica.

Conclusiones:

CeCo2As2 exhibe un efecto Nernst anómalo significativo, impulsado por estados electrónicos topológicos.
El estudio destaca la importancia de la topología impulsada por la correlación en los sistemas de retículo de Kondo para las propiedades termoeléctricas.
Este material sirve como una plataforma prometedora para explorar fenómenos topológicos y aplicaciones termoeléctricas.

Palabras clave:

efecto Nernst anómalo retículo de Kondo CeCo2As2 curvatura de Berry bandas planas topológicas electrónica de correlación

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