Fractal Conductance Fluctuations in Gold--Nanowires

Abstract

A detailed analysis of magneto-conductance fluctuations of quasiballistic gold-nanowires of various lengths is presented. We find that the variance $<(ΔG)^2> = < (G(B)-G(B+ΔB))^2>$ when analyzed for $ΔB$ much smaller than the correlation field $B_c$ varies according to $<(ΔG)^2>\propto ΔB^γ$ with $γ< 2$ indicating that the graph of $G$ vs. $B$ is fractal. We attribute this behavior to the existence of long-lived states arising from chaotic trajectories trapped close to regular classical orbits. We find that $γ$ decreases with increasing length of the wires.