Transient moment relaxation in high-temperature superconductors

The decays of the persistent supercurrent have been derived for several characteristic I-V relationships with few sample-dependent parameters. The results are compared with recent short-time flux-creep data in a short ``transient'' time window (10^-4--{10}²s). The results favor the I-V characteristics V∝exp[-({I}₀$/I${)}^{{{μ}}}$], as predicted by the collective-pinning and vortex-glass models. However, the {μ} so obtained is greater than 1, in contrast with that predicted. This may imply a different type of vortex elemental excitation observed in our low-field conditions.