Figure 1

Classical and quantum diffusion of H and D on Cu(001). (a) Arrhenius plot of the hopping rate of H ($\circ$) and D ($+$) between 80 and 9 K measured by single-atom tracking (80–65 K) and repeated imaging (63–9 K). The right axis gives the equivalent single particle diffusion constant, $D$, which is related to the hop frequency $\nu$ by the expression $D=1/4l^2\nu$, where the lattice constant $l=2.55\AA$. (b) Arrhenius plot of the hopping rate of H ($\circ$) and D ($+$) atoms determined by single-atom tracking between 65 and 80 K. (c) Log-log plot of the H hopping rate between 63 and 9 K determined by multiple imaging.Reuse & Permissions