Geometry dependent dephasing in small metallic wires

Abstract

Temperature dependent weak localization is measured in metallic nanowires in a previously unexplored size regime down to width $w=5$ nm. The dephasing time, $τ_ϕ$, shows a low temperature $T$ dependence close to quasi-1D theoretical expectations ($τ_ϕ \sim T^{-2/3}$) in the narrowest wires, but exhibits a relative saturation as $T \to 0$ for wide samples of the same material, as observed previously. As only sample geometry is varied to exhibit both suppression and divergence of $τ_ϕ$, this finding provides a new constraint on models of dephasing phenomena.