Resistive state of quasi-one-dimensional superconductors: Fluctuations vs. sample inhomogeneity

The shape of experimentally observed R(T) transition of thin superconducting wires is analyzed. Broadening of the transition in quasi-one-dimensional superconducting channels is typically associated with phase slip mechanism provided by thermal or quantum fluctuations. It is shown that consideration of inevitable geometrical inhomogeneity and finite dimensions of real samples studied in experiments is of primary importance for interpretation of results. The analysis is based on experimental fact that for many superconducting materials the critical temperature is a function of characteristic dimension of a low-dimensional system: film thickness or wire cross section.