Theory of self-diffusion in GaAs
  Ab initio molecular dynamics simulations are employed to investigate the dominant migration mechanism of the gallium vacancy in gaas as well as to assess its free energy of formation and the rate constant of gallium self-diffusion. our analysis suggests that the vacancy migrates by second nearest neighbour hops. the calculated self-diffusion constant is in good agreement with the experimental value obtained in ^69 GaAs/ ^71 GaAs isotope heterostructures and at significant variance with that obtained earlier from interdiffusion experiments in GaAlAs/GaAs-heterostructures. 
Michel Bockstedte and Matthias Scheffler