Flux Flow in Thin Type-I Superconducting Films

Analysis of Critical Power Loss in a Superconductor

“…Kim, Hempstead, and Strnad[9] have done considerable work on d. c. flux flow in type II superconductors. The experimental work of Tholfsen and Meissner[10] on dc flux flow in type I superconducting films leads them to agree with the considerable experimental and theoretical evidence referenced in their paper that fluxoid formation and flow in type I films is similar to that in type II materials. However, they have a point of disagreement with Kim et al[9] in which they claim a better fit to both their data and that of Kim et al with a slightly different mathematical relationship.…”

“…If we convert the Tholfsen and Meissner[10] data fitting result into a fluxoid flow viscosity, η, the result would be η = µφ H c (T) et al equation for η is generally accepted, it is the one that will be used here. However, in what follows, either expression, or any other, may be inserted where η appears.…”

Resistive current states in wide superconducting films in zero magnetic field

“…Prior to the discovery of PSCs and phase slip lines (PSLs), it was assumed that the transitional phase was brought about by the motion of Abrikosov vortices transverse to the current under the influence of the Lorentz force. The resistance created by this motion is reflected in the form of the linear and nonlinear parts of the vortex region of the I -V characteristic of the samples [14][15][16][17].…”

“…At the same time it was observed back in 1972 that, in addition to the typical vortex region at low currents, the I -V characteristics of wide films at high transport currents had a voltage-step structure [16] for which a physical explanation had not yet been found. The authors of [14,15] proposed that in wide films at currents larger than a certain instability current I * , a system of transverse alternating normal and superconducting domains is formed, and in this regime the mechanisms of flux flow do not have as important an influence on the shape of the I -V curves as in the low-current regime. Unfortunately, at that time those ideas had not received the necessary development.…”

Current states in superconducting films: Numerical results

“…Within this temperature interval, the film enters the vortex state at I > I c , although the temperature dependence of I c is similar to the case of a vortexfree narrow channel. An analogous behavior of the critical current in wide films has been registered in early experiments [21,22]. To explain such a specific dependence of I c (T ), it was supposed in [9] that the Pearl's vortices in moderately wide films may overcome the edge barrier at the edge current density ∼ (1 − T /T c ) 2 much smaller than the GL critical current density…”