LOGARITHMIC STEP FLUCTUATIONS IN VICINAL SURFACE - A MONTE-CARLO STUDY

Based on the terrace-step-kink (TSK) picture, the fluctuation property of a single step on the vicinal surface is studied by the Monte Carlo method. Logarithmic behavior of the squared step width W2(y) is similar to A(w) In y (y:distance between two points on the same step) is confirmed for both the free-fermion TSK model and the non-free-fermion solid-on-solid (SOS) step model. The calculated amplitude A(w) as a function of the step density rho verifies the universal form A(w) = 1/(pi2 rho2) for the free-fermion TSK model. For the SOS step model, A(w) deviates from the universal form as rho increases.