Evidence of quantum phase slip effect in titanium nanowires

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.