Electron transport properties of titanium nanowires were experimentally studied. Below the effective diameter ≲50 nm all samples demonstrated a pronounced broadening of the R(T) dependencies, which cannot be accounted for by thermal fluctuations. Extensive microscopic and elemental analyses indicate the absence of structural or/and geometrical imperfections capable of broadening the R(T) transition to such an extent. We associate the effect with quantum fluctuations of the order parameter.
Lehtinen, J. S., Sajavaara, T., Arutyunov, K. Y., Presnjakov, M. Y., & Vasiliev, A. L. (2012). Evidence of quantum phase slip effect in titanium nanowires. Physical Review B, 85, . https://doi.org/10.1103/physrevb.85.094508