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Control coherente de una transición de fase estructural de la superficie
Jan Gerrit Horstmann1, Hannes Böckmann1, Bareld Wit1
14th Physical Institute, Solids and Nanostructures, University of Göttingen, Göttingen, Germany.
Nature
|July 10, 2020
Resumen
Los científicos lograron el control óptico de una transición de fase en estado sólido utilizando pulsos láser precisos. Este método aprovecha la coherencia vibratoria para cambiar entre estados aislantes y metálicos, allanando el camino para nuevas funcionalidades de materiales.
Área de la Ciencia:
- Física de la materia condensada
- Ciencias de la superficie
- Química Física
Sus antecedentes:
- El control óptico activo es crucial para manipular la materia, permitiendo aplicaciones como la conmutación magnética totalmente óptica y las transiciones de fase inducidas por la luz.
- Las transiciones de metal a aislante en sólidos son objetivos clave para la manipulación óptica debido a los cambios ultrarrápidos en las propiedades electrónicas y de celosía.
- El papel de las coherencias en la eficiencia y los umbrales de estas transiciones sigue siendo en gran medida inexplorado.
Objetivo del estudio:
- Demostrar el control coherente de una transición de fase estructural entre el aislante y el metal.
- Investigar el impacto de la coherencia vibratoria en la eficiencia de conmutación en un sistema de superficie de estado sólido cuasi unidimensional.
Principales métodos:
- Utilizó un esquema de excitación de doble pulso de femtosegundo para la conmutación óptica.
- Se utiliza la difracción de electrones ultra rápida de baja energía (ULEED) para controlar la dinámica estructural.
- Aprovechar la coherencia vibratoria en modos estructurales específicos para gobernar la transición de fase.
Principales resultados:
- Con éxito cambió el sistema de un aislante a un estado metastable usando la excitación de doble pulso.
- Se han observado oscilaciones dependientes del retraso en la eficiencia de conmutación, lo que indica un control mediante coherencia vibratoria.
- Se ha demostrado un control coherente y selectivo del modo de transición de la fase estructural.
Conclusiones:
- El control coherente puede regular eficazmente las transiciones entre el aislante y el metal en sistemas de superficies de estado sólido.
- La coherencia vibratoria juega un papel crítico en la eficiencia de las transiciones de fase inducidas ópticamente.
- Este enfoque abre nuevas posibilidades para cambiar las funcionalidades químicas y físicas utilizando estados de no equilibrio metastables.
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