ISSN:
1434-6036
Keywords:
PACS. 75.45.+j Macroscopic quantum phenomena in magnetic systems – 75.50.Mm Magnetic liquids
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract: The tunneling of a giant spin at excited levels is studied theoretically in mesoscopic magnets with a magnetic field at an arbitrary angle in the easy plane. Different structures of the tunneling barriers can be generated by the magnetocrystalline anisotropy, the magnitude and the orientation of the field. By calculating the nonvacuum instanton solution explicitly, we obtain the tunnel splittings and the tunneling rates for different angle ranges of the external magnetic field ( θ H = π/2 and π/2 〈 θ H 〈 π). The temperature dependences of the decay rates are clearly shown for each case. It is found that the tunneling rate and the crossover temperature depend on the orientation of the external magnetic field. This feature can be tested with the use of existing experimental techniques.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1140/epjb/e20020117
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