Quantum conductance of In nanowires on Si(111) from first principles calculations

The quantum conductance of the paradigmatic quasi-one-dimensional In/Si(111) surface system is calculated for 4 x 1, 4 x 2 and 8 x 2 surface reconstructions. In agreement with experiment, we find the recently suggested formation of hexagons within the In nanowires [C. Gonzalez, F. Flores, J. Ortega, Phys. Rev. Lett. 96 (2006) 136101] to drastically modify the electron transport along the In chains. In contrast, the formation of trimers barely changes the quantum conductance.