Reconfiguration of charge density waves by surface nanostructures onTaS2

The transition metal dichalcogenide $1T-{\mathrm{TaS}}_2$ forms charge density waves due to the quasi-two-dimensionality of its electronic structure. Here we show how the growth of Rb nanowires on the surface of $1T-{\mathrm{TaS}}_2$ affects the superstructure of the charge density waves. Scanning tunneling microscopy and low-energy electron diffraction studies show the replacement of the normal ${\mathrm{TaS}}_2$ room temperature $\sqrt{13}\times \sqrt{13}$ phase by $c(2\mathrm{}\sqrt{3}\times 4)\mathrm{rect}.\mathrm{}$ and $3\times 3$ superstructures depending on the state of nanowire growth. Furthermore, angle resolved photoemission studies give evidence for a metal to semiconductor transition when the superstructure of the charge density wave is changed. These changes are discussed in the context of nanowire growth, which is accompanied by a change in the dimensionality of the electronic states of $1T-{\mathrm{TaS}}_2.$