Current-voltage characteristic of narrow superconducting wires: Bifurcation phenomena

摘要

The current-voltage characteristics of long and narrow superconducting channels arq investigated using the time-dependent Ginzburg-Landau equations for the complex order parameter. We found out that the steps in the current-voltage characteristic can be associated with bifurcations of either a steady-state or oscillatory solution. We revealed typical instabilities which induced the singularities in current-voltage characteristics, and analytically estimated the period of oscillations and average voltage in the vicinity of the critical currents. Our results show that these bifurcations can substantially complicate dynamics of the order parameter and eventually lead to the, appearance of such phenomena as multistability and chaos. The discussed bifurcation phenomena sheds a light on some recent experimental findings.