High-temperature superconducting fault current microlimiters

High-temperature superconducting microbridges implemented with YBa2Cu3O7-δ thin films are shown to be possible fault current limiters for microelectronic devices with some elements working at temperatures below the superconducting critical temperature and, simultaneously, under very low power conditions (below 1 W). This is the case in the important applications of superconductors as SQUID based electronics and technologies for communication or infrared detectors. In this paper it is shown that the good thermal behavior of these microlimiters allows working in a regime where even relatively small faults induce their transition to highly dissipative states, dramatically increasing their limitation efficiency. The conditions for optimal refrigeration and operation of these microlimiters are also proposed.