Magnetic levitation, suspension, and superconductivity: Macroscopic and mesoscopic

Journal Article · Thu Feb 01 04:00:00 EST 1996 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.53.3506· OSTI ID:278732

Haley, S B; Fink, H J ^[1]

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1. Department of Electrical and Computer Engineering, University of California, Davis, California, 95616 (United States)

The levitation state of a large magnetic sphere held in equilibrium above a thick superconducting layer in the Meissner state is a single temperature-independent state as long as the maximum magnetic field at the superconducting (SC) surface does not exceed the critical field {ital H}{sub {ital c}}({ital T}). In contrast, a magnetic microsphere trapped by a superconducting microring exhibits very different behavior. When the radius {ital b} of the SC ring is of the same order as the Ginzburg-Landau coherence length {xi}({ital T}), the system exhibits, in general, a small set of distinct, quantized, temperature-dependent levitation and suspension states. For certain discrete values of {ital b} the flux in the ring is quantized, and the levitation and suspension heights are temperature independent. An abrupt temperature induced transition in the suspension height is also found for a special set of parameters. {copyright} {ital 1996 The American Physical Society.}

• OSTI ID: 278732
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 6 Vol. 53; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
COHERENCE LENGTH
GINZBURG-LANDAU THEORY
LEVITATION
MAGNETIC FIELDS
MAGNETIC FLUX
MEISSNER-OCHSENFELD EFFECT
SPHERES
SUPERCONDUCTIVITY
TEMPERATURE DEPENDENCE