Pair-breaking model for disorder in two-dimensional superconductors

Measurements of resistive transitions, critical fields, and magnetoconductance as a function of increasing normal-state sheet resistance $R_N$ reveal the systematics of a pronounced change from superconducting to insulating behavior in thin $\frac{\mathrm{In}}{\mathrm{In}{\mathrm{O}}_x}$ composite films. With increasing $R_N$, a rapid suppression of the transition temperature together with a decreasing critical-field slope parameter are observed. These results are modeled using a pair-breaking formalism in which the pair-breaking rate is found to be proportional to $R_N$ and independent of temperature.