On the atomic scale, this misorientation produces a mismatch between the atoms in the top (blue) crystal and the bottom (grey) crystal. If we were able to look down on the interface between the two crystals, the atoms at the interface would resemble the sketch at the right.

In some regions, the atoms in the top (blue) crystal are well aligned with the atoms in the bottom (grey) crystal. These atoms form strong chemical bonds with one another. In other regions, the top and bottom atoms do not align well. These misaligned areas form a square grid or Moiré pattern in the sketch at right. Chemically speaking, these misaligned regions correspond to dislocations -- lines of poor chemical bonding.

These dislocations form the basis of our new nanofabrication technique. By controlling the angle between the top and bottom crystals, we can precisely control the spacing of the dislocations.