Quantum tunneling of domain walls in ferromagnets

We present a theoretical study of the quantum depinning of domain walls. Our approach extends earlier work by Stamp and confirms his suggestion that quantum tunneling of domain walls in ferromagnets may reveal itself at a macroscopic level in a manner similar to the Josephson effect in superconducto...

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Detalles Bibliográficos
Autores: Chudnovsky, Eugene M., 1948-, Iglesias, Òscar, Stamp, P. C. E.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:1992
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/9742
Acceso en línea:https://hdl.handle.net/2445/9742
Access Level:acceso abierto
Palabra clave:Magnetisme
Histèresi
Efecte túnel
Física de l'estat sòlid
Magnetism
Hysteresis
Tunneling (Physics)
Solid state physics
Descripción
Sumario:We present a theoretical study of the quantum depinning of domain walls. Our approach extends earlier work by Stamp and confirms his suggestion that quantum tunneling of domain walls in ferromagnets may reveal itself at a macroscopic level in a manner similar to the Josephson effect in superconductors. The rate of tunneling of a domain wall through a barrier formed by a planar defect is calculated in terms of macroscopic parameters of the ferromagnet. A universal behavior of the WKB exponent in the limit of small barriers is demonstrated. The effect of dissipation on the tunneling rate is studied. It is argued that quantum diffusion of domain walls apparently explains a nonthermal magnetic relaxation observed in some materials at low temperatures.