Self-organized one-dimensional electron systems on a low-symmetry oxide surface

A new one-dimensional electron gas, metallic over a temperature range of 1-800 K, is predicted on the kappa-Al2O3(00 (1) over bar) 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.