Current-induced highly dissipative domains in high-T-c thin films

Article

关键词: MAGNETIC PENETRATION DEPTH;    HIGH-CURRENT DENSITIES;    FAULT CURRENT LIMITER;    PHASE-SLIP CENTERS;    SUPERCONDUCTING FILMS;    TEMPERATURE-DEPENDENCE;    INSTABILITY;    STATE;    MICROBRIDGES;    RESISTANCE;   

DOI  :  10.1103/PhysRevB.66.014522

来源: SCIE

【 摘 要 】

We have investigated the resistive response of high-T-c thin films submitted to a high density of current. For this purpose, current pulses were applied into bridges made of Nd1.15Ba1.85Cu3O7-delta and Bi2Sr2CaCu2O8+delta. By recording the time-dependent voltage, we observe that at a certain critical current j*, a highly dissipative domain develops somewhere along the bridge. The successive formation of these domains produces stepped I-V characteristics. We present evidence that these domains are not regions with a temperature above T-c, as for hot spots. In fact this phenomenon appears to be analog to the nucleation of phase-slip centers observed in conventional superconductors near T-c, but here in contrast they appear in a wide temperature range. Under some conditions, these domains will propagate and destroy the superconductivity within the whole sample. We have measured the temperature dependence of j* and found a similar behavior in the two investigated compounds. This temperature dependence is just the one expected for the depairing current, but the amplitude is about 100 times smaller.

【 授权许可】

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