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Dos fases de vórtice coexistentes en el régimen de efecto pico en un superconductor
M Marchevsky1, M J Higgins, S Bhattacharya
1NEC Research Institute, Princeton, New Jersey 08540, USA. marchev@research.nj.nec.com
Nature
|February 24, 2001
Resumen
El efecto pico en superconductores como el NbSe2 se explica por dos fases de materia vórtice coexistentes con diferentes fuerzas de fijación. Esta fase de coexistencia impulsa una transición impulsada por el desorden, resolviendo un misterio de 40 años.
Área de la Ciencia:
- Física de la materia condensada Física de la materia condensada Física de la materia condensada Física de la materia condensada Física de la materia condensada
- Investigación de la superconductividad.
- Ciencia de los materiales ciencia de los materiales.
Sus antecedentes:
- Los superconductores de tipo II exhiben una anomalía de corriente crítica cerca de la transición del superconductor al metal normal, conocida como el efecto pico.
- Este efecto pico, donde los picos críticos de corriente antes de desaparecer, ha permanecido inexplicable durante 40 años.
Objetivo del estudio:
- Para investigar el mecanismo subyacente del efecto pico en NbSe2.2.
- Para visualizar la distribución en el espacio real de la corriente crítica en la fase de vórtice.
Principales métodos:
- Utilizó un microscopio de Hall de escaneo.
- Se visualizó la distribución en el espacio real de la corriente crítica en NbSe2.2.
Principales resultados:
- Identificó dos fases distintas de vortex-materia con diferentes fuerzas de fijación que coexisten a escala macroscópica en el régimen de efecto pico.
- Se demostró que la composición y la transformación de estas fases explican los efectos del historial y las respuestas anómalas de voltaje.
Conclusiones:
- La coexistencia de dos fases de materia vórtice es responsable del efecto pico en NbSe2.2.
- Esta coexistencia de fases es un sello distintivo de una transición de fase no térmica impulsada por el desorden.
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