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Fase Hall cuántica helicoidal en el grafeno sobre el SrTiO

Louis Veyrat¹, Corentin Déprez¹, Alexis Coissard¹

¹Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel, 38000 Grenoble, France.

Science (New York, N.Y.)

|February 15, 2020

Resumen

Los investigadores lograron una fase topológica en grafeno utilizando un sustrato de titanato de estroncio, lo que permite un transporte robusto de bordes helicoidales. Este avance abre las puertas para la espintrónica y la computación cuántica topológica.

Área de la Ciencia:

Física de la materia condensada
Ciencias de los materiales

Sus antecedentes:

El estado fundamental del grafeno bajo campos magnéticos se predijo teóricamente que sería un aislante topológico Hall cuántico.
Las observaciones experimentales a menudo muestran un estado aislante debido a las interacciones de celosía, que difieren de las predicciones teóricas.

Objetivo del estudio:

Realizar experimentalmente la fase topológica predicha en el grafeno.
Investigar el papel del cribado de interacción de Coulomb en el logro de esta fase.

Principales métodos:

Utilizando un sustrato de titanato de estroncio (SrTiO3) con una alta constante dieléctrica para examinar las interacciones de Coulomb en el grafeno.
Aplicando campos magnéticos perpendiculares para ajustar el nivel de Landau cero del grafeno.

Principales resultados:

Logró una fase topológica en el estado fundamental del grafeno.
Se observó un transporte robusto de bordes helicoidales en campos magnéticos bajos (1 tesla) y temperaturas elevadas (hasta 110 K) a distancias de micrones de largo.

Conclusiones:

Demostró un método para acceder al estado aislante cuántico topológico del grafeno.
La plataforma de grafeno desarrollada es prometedora para las aplicaciones de computación cuántica y topológica.

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