Driven Vortex States and Relaxation in Single Crystal $YBa_2Cu_4O_8$
Abstract
The vortex response to various ac-drives has been studied in high quality $YBa_2Cu_4O_8$ single crystals. Well within the vortex solid phase a re-entrant resistive state has been observed that is characterized by long relaxation times. Pulse current response and IV characteristics reveal that in this state the driven vortex system relaxes in a way to increase t he effective pinning force. A phenomenological model accounts for the observed features, in particular the clock-wise hysteresis of the IV-curves and the increase of the apparent critical current with applied current amplitude.
- Publication:
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arXiv e-prints
- Pub Date:
- April 1998
- DOI:
- 10.48550/arXiv.cond-mat/9804121
- arXiv:
- arXiv:cond-mat/9804121
- Bibcode:
- 1998cond.mat..4121M
- Keywords:
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- Condensed Matter - Superconductivity
- E-Print:
- 5 pages, 4 figures, submitted to PRL