Reentrant ac Magnetic Susceptibility in Josephson-Junction Arrays

Journal Article · Sun Jun 01 00:00:00 EDT 1997 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.78.4625· OSTI ID:531853

Araujo-Moreira, F M; Barbara, P; Cawthorne, A B; Lobb, C J ^[1]

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1. Center for Superconductivity Research, Department of Physics, University of Maryland at College Park, College Park, Maryland 20742-4111 (United States)

We have measured the complex ac magnetic susceptibility of unshunted Josephson-junction arrays as a function of temperature T , amplitude of the excitation field h{sub ac} , and external magnetic field H{sub dc} . For small h{sub ac} Meissner screening occurs. For larger h{sub ac} , however, the screening is reentrant in T . This reentrance is not thermodynamic but dynamic and arises from the paramagnetic contribution of multijunction loops. This result gives an alternative explanation of the paramagnetic Meissner effect observed in granular superconductors. Experimental results are in agreement with a simplified model based on a single loop containing four junctions. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 531853
• Journal Information: Physical Review Letters, Vol. 78, Issue 24; Other Information: PBD: Jun 1997
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
JOSEPHSON JUNCTIONS
MAGNETIC SUSCEPTIBILITY
TEMPERATURE DEPENDENCE
MEISSNER-OCHSENFELD EFFECT
NIOBIUM
SUPERCONDUCTIVITY
PARAMAGNETISM
MAGNETIC FLUX