Self-replicating twins in nanowires.

Based on molecular-dynamics simulations validated with quantum-mechanical calculations, we predict that (111) twin planes in a [111]-oriented GaAs nanowire attain attractive interactions mediated by surface strain. This gives rise to a self-replication mechanism that continuously generates a twin superlattice in a nanowire during growth. We demonstrate significant implications of the twin-twin interaction for the electronic, mechanical, and chemical properties of nanowires. These unique properties suggest potential applications such as catalysts for solar fuel production and nanoscale mechanical dampers.