The precise driving force of the phase transition in indium nanowires on Si(111) has been controversial whether it is driven by a Peierls instability or by a simple energy lowering due to a periodic lattice distortion. The present van der Waals (vdW) corrected hybrid density functional calculation predicts that the low-temperature 8x2 structure whose building blocks are indium hexagons is energetically favored over the room-temperature 4x1 structure. We show that the correction of self-interaction error and the inclusion of vdW interactions play crucial roles in describing the covalent bonding, band-gap opening, and energetics of hexagon structures. The results manifest that the formation of hexagons occurs by a simple energy lowering due to the lattice distortion, not by a charge density wave formation arising from Fermi surface nesting.
@article{arxiv.1303.1001,
title = {Driving force of phase transition in Indium nanowires on Si(111)},
author = {Hyun-Jung Kim and Jun-Hyung Cho},
journal= {arXiv preprint arXiv:1303.1001},
year = {2013}
}