Atomic structure of the $\mathrm{GaAs}\left(1\mathrm{}¯1¯3¯\right)B(8\mathrm{}\times 1)$ surface reconstruction

Atomically resolved scanning tunneling microscopy and low-energy electron diffraction were used to determine the surface structure of the $\mathrm{GaAs}\left(1\mathrm{}¯1¯3¯\right)B$ surface prepared by molecular beam epitaxy. An $(8\mathrm{}\times 1)$ reconstruction was found, which forms by exchanging Ga and As atoms analogously to the $\mathrm{GaAs}\mathrm{}\left(113\right)A(8\mathrm{}\times 1)$ reconstruction proposed by Wassermeier et al. [Phys. Rev. B 51, 14 721 (1995)]. The characteristic components of the A and B $(8\mathrm{}\times 1)$ surface reconstructions are dimers forming zigzag chains along $\left[3¯3¯2\right]$ in two atomic levels. While on the A surface the dimers are built of As atoms, on the B surface Ga atoms form the dimers. The morphology of the $\mathrm{GaAs}\left(1\mathrm{}¯1¯3¯\right)B(8\mathrm{}\times 1)$ surface is rather smooth and does not show the typical roughness known for the $\mathrm{GaAs}\mathrm{}\left(113\right)A(8\mathrm{}\times 1)$ surface.