Evidence for vortex tunnel dissipation in deoxygenated YBa_(2)Cu_(3)O_(6.4) thin films
We report on transport and magnetic relaxation measurements of deoxygenated YBa_(2)Cu_(3)O_(7-δ) thin films. Strongly oxygen depleted samples with δ=0.6 are produced to ensure the pure two-dimensional nature of the vortex system. Linear resistivity shows a temperature dependence according to ρ_(lin^...
| Autores: | , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2001 |
| País: | España |
| Institución: | Universidad Complutense de Madrid (UCM) |
| Repositorio: | Docta Complutense |
| Idioma: | inglés |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/59642 |
| Acceso en línea: | https://hdl.handle.net/20.500.14352/59642 |
| Access Level: | acceso abierto |
| Palabra clave: | 537 Ultrathin superconducting films Glass phase-transition Quantum creep Magnetic-relaxation II superconductors T-G=0 K Vortices Transport. Electricidad Electrónica (Física) 2202.03 Electricidad |
| Sumario: | We report on transport and magnetic relaxation measurements of deoxygenated YBa_(2)Cu_(3)O_(7-δ) thin films. Strongly oxygen depleted samples with δ=0.6 are produced to ensure the pure two-dimensional nature of the vortex system. Linear resistivity shows a temperature dependence according to ρ_(lin^(α))exp[-((T_(0)/T)^(p)]. T_(0) takes a value of 230±10 K over the whole field range, and p changes from 1±0.03 at 2 T to 0.70±0.03 at 8 T. For fields higher than 4 T, dissipation in the linear regime (low current densities) is dominated by quantum variable range hopping ~VRH! of vortices. At high current densities and low temperatures, nonlinear dissipation takes place by quantum creep, characterized by a temperature-independent resistivity and by a saturation of the magnetic relaxation rate. |
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