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Quantum Creep in Y_{1-x}Pr_{x}Ba_{2}Cu_{3}O_{7}$ Crystals: Magnetic Relaxation and Transport

T. Stein·G. A. Levin·C. C. Almasan·D. A. Gajewski·M. B. Maple
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Abstract

We report transport and magnetic relaxation measurements in the mixed state of strongly underdoped Y_{1-x}Pr_{x}Ba_{2}Cu_{3}O_{7} crystals. A transition from thermally activated flux creep to temperature independent quantum flux creep is observed in both transport and magnetic relaxation at temperatures T * 5 K. Flux transformer measurements indicate that the crossover to quantum creep is preceded by a coupling transition. Based on these observations we argue that below the coupling transition the current is confined within a very narrow layer beneath the current contacts.

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T. Stein, G. A. Levin, C. C. Almasan, D. A. Gajewski, M. B. Maple. 1999-02-09. Quantum Creep in Y_{1-x}Pr_{x}Ba_{2}Cu_{3}O_{7}$ Crystals: Magnetic Relaxation and Transport. https://doi.org/10.1103/physrevlett.82.2955

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