Electrical tuning of the kinetic inductance of high temperature superconductors

A current controlled delay in the time of flight of electrical picosecond pulses in a YBa2Cu3O7 spiral delay line has been investigated using optoelectronic sampling techniques. The transmission line is a microwave stripline on the LaAlO3 substrate and is passivated with the contact pads open. The measured delay time clearly shows a squared dependence on the applied current, in good agreement with Ginzburg–Landau theory for the case of a uniform current density through a thin film.