Abstract
Based on molecular-beam-epitaxy scanning-tunneling-microscopy (STM) observations, we report a 6×2 reconstructed surface formed in the initial stage of highly strained InAs growth on GaAs(001). Atomic-resolution STM images show several unique features in its structure and morphology, compared to other InAs or GaAs(001) reconstructions. We have documented that the formation of the 6×2 surface is critical for desirable layer-by-layer growth and proposed a dimer-based structure model.