MODULATION OF KINETIC INDUCTANCE OF HIGH T(C) SUPERCONDUCTING THIN-FILMS WITH BIAS CURRENT

Kinetic inductance of high T(c) superconducting thin films is studied using numerical simulation of the Ginzburg-Landau (GL) theory. It is s hown that a current distribution in the film changes nonlinearly with a bias current supplied to the film, which results from the nonlinear properties of the GL equation. Using the current distribution, the kin etic inductance of the film is obtained as a function of the bias curr ent. It is shown that the kinetic inductance is constant for low bias currents, and increases nonlinearly with the bias current when the bia s current becomes large. The effect of the film geometry on the modula tion of the kinetic inductance is quantitatively studied. Analytical s olutions for the current distrubiton and the kinetic inductance are al so obtained, which agree well with the simulation results. The modulat ion of the kinetic inductance with the bias current predicted from the theory is partly confirmed from experiments using YBaCuO films.