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Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope
Published on: March 24, 2019
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Ferromagnetismo de alta temperatura inducido por la foto en YTiO
A S Disa1,2, J Curtis3,4, M Fechner5
1Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany. asd47@cornell.edu.
Nature
|May 3, 2023
Resumen
Los investigadores utilizaron la luz para aumentar el ferromagnetismo en YTiO3, logrando un orden magnético transitorio de hasta 80K, mucho más allá de su límite habitual de 27K. Este control óptico ofrece nuevas formas de diseñar las propiedades de los materiales cuánticos.
Área de la Ciencia:
- Ciencia de los materiales cuánticos
- Física de la materia condensada
- Ingeniería de materiales
Sus antecedentes:
- Las degeneraciones y las interacciones frustradas en los materiales cuánticos a menudo suprimen las fases electrónicas o magnéticas deseadas.
- Los métodos tradicionales para diseñar estas fases implican la modificación de la estructura atómica, limitada por las restricciones termodinámicas.
- El titanato de yttrio (YTiO3) exhibe ferromagnetismo suprimido con una baja temperatura de Curie (Tc = 27K).
Objetivo del estudio:
- Para investigar la manipulación totalmente óptica y selectiva de la dinámica de la celosía cristalina.
- Mejorar y estabilizar el ferromagnetismo de alta temperatura en YTiO3 más allá de sus limitaciones de equilibrio.
- Explorar las funcionalidades de no equilibrio inducidas por la luz en materiales cuánticos.
Principales métodos:
- Se utilizó la excitación óptica de modo selectivo de la red cristalina de YTiO3 a 9 THz.
- Investigó el impacto de la excitación de un modo de rotación de oxígeno específico en las propiedades magnéticas.
- Se analizaron los cambios dinámicos inducidos por la luz en los orbitales t2g de titanio (Ti) y su efecto en la competencia de fase magnética.
Principales resultados:
- Se logra una saturación magnética completa a bajas temperaturas en YTiO3.
- El ferromagnetismo transitorio realizado hasta temperaturas de no equilibrio (Tneq) superiores a 80K, casi el triple del Tc termodinámico.
- El ferromagnetismo inducido por la luz observado es metastable en escalas de tiempo de nanosegundos.
Conclusiones:
- La manipulación de celosía totalmente óptica puede mejorar y estabilizar dinámicamente el ferromagnetismo en materiales cuánticos.
- Los cambios inducidos por la luz en los orbitales cuasi degenerados son clave para superar las limitaciones de equilibrio.
- Este enfoque permite la ingeniería dinámica de funcionalidades de no equilibrio para aplicaciones prácticas.
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