Current-Induced Step Bending Instability on Vicinal Surfaces
  We model an apparent instability seen in recent experiments on current induced step bunching on Si(111) surfaces using a generalized 2D BCF model, where adatoms have a diffusion bias parallel to the step edges and there is an attachment barrier at the step edge. We find a new linear instability with novel step patterns. Monte Carlo simulations on a solid-on-solid model are used to study the instability beyond the linear regime. 
Da-Jiang Liu, John D. Weeks, and Daniel Kandel