Self-Organized One-Dimensional Electron Systems on a Low-Symmetry Oxide Surface

Abstract

A new one-dimensional electron gas, metallic over a temperature range of 1–800 K, is predicted on the $\kappa \mathrm{\text{−}}{\mathrm{A}\mathrm{l}}_2{\mathrm{O}}_3(00\overline{1})$ surface by means of density-functional theory (DFT) calculations. The robustness against the Peierls instability is tested using a tight-binding model with DFT-calculated parameters. The critical transition temperature $T_c$ is shown to be smaller than 1 K. The low value of $T_c$ makes this system suited for studying Luttinger-liquid (LL) behavior. For future experiments, the LL parameters are estimated, yielding a high electrical conductivity.