Fermi surface tuning in two-dimensional surface systems

Abstract

Competing electronic interactions can be used to tune materials into different phases withinteresting and sometimes exotic properties, ranging from magnetic long-range order tosuperconductivity. Such electronic interactions are particularly pronounced inlow-dimensional systems, where electronic correlation is enhanced. On surfaces, theelectronic states are easily accessible for manipulation by doping, adsorption or quantumconfinement. A deliberate shift of the Fermi surface of 2D or 1D electron states can have asignificant influence on chemical activity, adsorbate–adsorbate interactions, surfacediffusion etc. More strikingly, it may drive phase transitions and can perhaps be used torealize Peierls-distorted, magnetically ordered and even superconducting phases in twodimensions. Using the Br/Pt(110) system as a case study, the possibility and the problemsof a (quasi)continuous variation of a Peierls phase by Fermi surface tuning are examined.