Tunneling I-V characteristics between very narrow titanium nanowires and "massive" superconducting aluminum were measured. The clear trend was observed: the thinner the titanium electrode, the broader the singularity at eV = [delta]1(Al)+[delta]2(Ti). The phenomenon can be explained by broadening of the gap edge of the quasi-one-dimensional titanium channels due to quantum fluctuations of the order parameter modulus |?2|. The range of the nanowire diameters, where the effect is pronounced, correlates with dimensions where the phase fluctuations of the complex superconducting order parameter [delta] = |[delta]|ei[phi], the quantum phase slips, broadening the R(T) dependencies, have been observed.
- quasi-one-dimensional superconductivity
- quantum fluctuations