THE INFLUENCE OF STEP STEP INTERACTIONS ON STEP WANDERING

We derive relationships between the amount of step wandering and the strength of step-step interactions to aid interpretation of scanning tunneling microscopy images of steps on surfaces. We make contact with well-established results for the statistical mechanics of interfacial wandering. In particular, we use the analogy between a step meandering in a potential and a quantum-mechanical particle moving in a one-dimensional potential well. We also set out an approximate procedure for computing the terrace-width distribution for non-interacting steps using free-fermion techniques, and show using Monte Carlo that the resulting temperature-independent distribution is a good aproximation until remarkably high temperatures.