Structure tuning by Fermi-surface shifts in low-dimensional systems

In low-dimensional systems, electron-electron correlation as well as electron-phonon coupling is enhanced. This tends to link the geometry to the Fermi-surface position, for instance via formation of charge-density waves. The quasi-one-dimensional c(2 x 2)-Br/Pt(110) surface system is used here to explore this effect. NO adsorption gives rise to a considerable Fermi-surface shift and causes the system to go through a succession of complex phases comprising commensurate, long-range-ordered structures, as well as periodic and chaotic soliton lattices. The structural evolution is in qualitative agreement with the predictions of the discrete Frenkel-Kontorova model. (Some figures in this article are in colour only in the electronic version).