IS THERE AN ELASTIC ANOMALY FOR A (001) MONOLAYER OF INAS EMBEDDED IN GAAS

When a coherently grown (001)-oriented layer of InAs is embedded in a GaAs host, the coherency strain induces a perpendicular distortion of the embedded layer, predicted by continuum elasticity theory to be epsilon(perpendicular-to) = 7.3 %. Brandt, Ploog, Bierwolf, and Hohenstein, [Phys. Rev. Lett. 68, 1339 (1992)] have described a high-resolution electron microscopic analysis of such buried layers that appears to reveal a breakdown of continuum elasticity theory in the limit of monolayer films. In particular, they found for a single monolayer of InAs a lattice distortion that corresponds to epsilon(perpendicular-to) = 12.5%. Here we report on an investigation into whether a first-principles local-density total energy minimization shows such an elastic anomaly in the monolayer limit. We find that it does not.