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El orden antiferromagnético como el estado fundamental en competencia en Nd1.85Ce0.15CuO4 dopado con electrones
H J Kang1, Pengcheng Dai, J W Lynn
1Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996-1200, USA.
Nature
|May 30, 2003
Resumen
La superconductividad de alta temperatura de transición en los óxidos de cobre compite con el antiferromagnetismo. Este estudio revela el orden antiferromagnético como un estado fundamental universal en estos materiales, independientemente del tipo de dopaje.
Área de la Ciencia:
- Física de la materia condensada Física de la materia condensada
- Ciencia de los materiales Ciencia de los materiales.
- Materiales Cuánticos Los materiales cuánticos son los materiales cuánticos.
Sus antecedentes:
- La superconductividad en los óxidos de cobre de alta temperatura de transición (alta Tc) es un fenómeno complejo.
- La comprensión de los estados de fondo en competencia es crucial para explicar la superconductividad de alta T (c).
- El antiferromagnetismo se predice teóricamente que es el estado fundamental competidor.
Objetivo del estudio:
- Para determinar la naturaleza del estado fundamental que compite con la superconductividad en los óxidos de cobre de alto T.
- Para establecer si este estado fundamental competitivo es universal en diferentes tipos de dopaje (electrón vs agujero).
- Para investigar la transición de fase cuántica de los estados superconductores a los estados antiferromagnéticos.
Principales métodos:
- Las mediciones de transporte en Nd1.85Ce0.15CuO4.4, dopado con electrones.
- Experimentos de dispersión de neutrones en Nd1.85Ce0.15CuO4.4 dopado con electrones.
- Aplicación de campos magnéticos para alcanzar el campo crítico superior (B) (c2)).
Principales resultados:
- Se observó un estado antiferromagnético estático, proporcionado y ordenado de largo alcance en materiales dopados con electrones.
- El momento magnético inducido escalaba linealmente con el campo aplicado hasta la saturación en B(c2).
- Este hallazgo, combinado con estudios previos sobre materiales dopados con agujeros, confirma el antiferromagnetismo como un estado fundamental competidor.
Conclusiones:
- El orden antiferromagnético es un estado fundamental universal que compite en los óxidos de cobre de alto T (c).
- Esta universalidad es válida independientemente de si el dopaje está basado en electrones o en agujeros.
- El estudio proporciona una visión crítica de la física fundamental que rige la superconductividad de alta T (c).
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