Interchain vacancy migration on GaAs(110)

At the (110) surface of a III–V semiconductor, the atoms are arranged in zigzag chains. If a surface vacancy is to move to a nearest‐neighbor sublattice site, it must migrate within these chains. The scanning‐tunneling‐microscopy observations reported here, however, demonstrate that As vacancies on GaAs(110) prefer to move between zigzag chains. This phenomenon can be understood in terms of simple bond‐breaking and rebonding arguments, and from barrier heights calculated using constrained molecular dynamics.