With a Si~001! vicinal surface in mind, we study step wandering instability on a vicinal surface with an anisotropic surface diffusion whose orientation dependence alternates on each consecutive terrace. In a conserved system step wandering takes place with step-up adatom drift. Repulsive interaction between steps is found indispensable for the instability. Monte Carlo simulation with a strong repulsive step interaction confirms the result of linear stability analysis, and further shows that in-phase step wandering produces straight grooves. Grooves widen as their amplitudes increase in proportion to the square root of time.
Repulsion-mediated step wandering on a Si(001)vicinal face
SC-PR-HIROSE-Y-PhysRevB_67_125408.pdf
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