Vortex-ring nucleation by thermal activation and quantum-tunneling processes in high-Tc superconductors is discussed. The nonlinear resistance scales as eν-(J/J)ν. Thermal activation yields a critical index of v = 1, while quantum tunneling (without normal current dissipation) yields a critical index of v = 2. Current-voltage characteristics were measured on both disordered (low-Jc), ordered (c axis normal to the film plane, high-Jc) Y-Ba-Cu-O films, and microbridges below Tc. The data were examined in terms of both thermal-activation and quantum-nucleation models. For the disordered films, the v = 1 scaling law is in reasonable agreement with data, while v = 2 scaling is required to explain the results of the ordered films at low temperatures. For the microbridges, the v = 2 scaling extends even to high temperatures.


Originally published in Physical Review B 45, 3048-3053 (1992). doi 10.1103/PhysRevB45.3048 (http://link.aps.org/doi/10.1103/PhysRevB.45.3048).


thermal activation, quantum tunneling processes, nucleation, vortex rings, high Tc, nonlinear resistance scales

Subject Categories

Tunneling (Physics), Superconductors


Electromagnetics and photonics | Other Electrical and Computer Engineering


American Physical Society

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Copyright 1992 American Physical Society

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American Physical Society

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