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

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.

5 Pages, 3 figures

References in corpus (1)

• Plastic vortex-creep in YBa${}_2$Cu${}_3$O${}_{7-x}$ crystals

Cited by in corpus (5)

• Record dynamics and the observed temperature plateau in the magnetic creep rate of type II superconductors
• Creep of superconducting vortices in the limit of vanishing temperature: A fingerprint of off-equilibrium dynamics
• Aging and memory phenomena in magnetic and transport properties of vortex matter: a brief review
• Dynamics of Flux Creep in Underdoped Single Crystals of Y_1-xPr_xBa_2Cu_3O_7-d
• Quantum vortex tunneling in $YB{a}_{2}C{u}_3{O}_{7-\delta }$ thin films