Nanostructured surfaces: Dimensionally constrained electrons and correlation

Abstract

This article examines dimensionally constrained electrons and electronic correlation in nanostructured surfaces. Correlation effects play an important role in spatial confinement of electrons by nanostructures. The effect of correlation will become increasingly dominant as the dimensionality of the electron wavefunction is reduced. This article focuses on quasi-one-dimensional (quasi-1D) confinement, i.e. more or less strongly coupled one-dimensional nanostructures, with occasional reference to 2D and 0D systems. It first explains how correlated systems exhibit a variety of electronically driven phase transitions, and especially the phases occurring in the generic phase diagram of correlated materials. It then describes electron–electron and electron–phonon interactions in low-dimensional systems and the phase diagram of real quasi-1D systems. Two case studies are considered: metal chains on silicon surfaces and quasi-1D structures on metallic surfaces. The article shows that spontaneous symmetry breaking occurs for many quasi-1D systems on both semiconductor and metal surfaces at low temperature.