Fig. 4: STM topography and tunneling spectra on PtxTi1−xSe2.
a 14 nm × 14 nm TiSe2 topography image acquired at 4 K, I = 20 pA, and V = 100 mV. The orange circles enclose CDW maxima. The inset represents a sketch of the CDW order distribution in the top Se layer. The large (small) yellow dots indicate CDW maxima (minima). b 14 nm × 14 nm topography image of x = 0.02 Pt-doped TiSe2 acquired at 4 K, I = 200 pA, and V = 50 mV. The red line indicates a CDW domain wall. The orange circles enclose CDW maxima. The inset is a magnified view of the region within the black square. The orange line shows the π-shift between domains. On one side of the domain wall, the orange line intersects the atoms while on the other side, it passes between the atoms. c 14 nm × 14 nm topography image of x = 0.1 Pt doped TiSe2 acquired at 4 K, I = 150 pA, and V = 100 mV. The orange circles enclose CDW maxima. d Most common spectra measured for x = 0, 0.02, 0.1 doping. e Selective inverse Fourier transform of CDW peaks calculated from b. The red line indicates the position of the CDW domain wall. The inset is a magnified view of the area within the black box and the orange lines show the π-shift between domains. f dI/dV image recorded at V = −20 mV on the same area shown in c. g Averaged spectra measured on areas 1, 2, 3, and 4 of f. h dI/dV spectra averaged over the entire area of f. The inset shows the difference between the averaged spectrum and the polynomial fit. In the topographies data, bright colors and dark colors correspond to higher and lower heights respectively, while they correspond to higher and lower densities of states in dI/dV data, respectively.
