A novel technique developed by our group uses a scanning tunneling microscope (STM) to substitute atoms into a semiconductor one atom at a time. This technique has been used to assemble a magnetic semiconductor, manganese-doped gallium arsenide (Ga1‑xMnxAs), atom by atom.
Published in Nature:
Atom-by-Atom Substitution of Mn in GaAs and Visualization of their Hole-Mediated Interactions, D. Kitchen, A. Richardella, J.-M. Tang, M. E. Flatté, A. Yazdani, Nature 442, 436 (2006). (Article)