Figure 1

(Color online) Schematics of the (a) atomic and (b) electronic structures of $\text{Si}\left(111\right)4\times 1\text{-In}$. The wire consists of zigzag In rows (large spheres) sandwiched by Si rows (small spheres) on the topmost layer of Si(111). Measured energy bands (ARPES intensity distributions in the energy-momentum space) for the (c) pristine and (d) Na-deposited $\text{In}/\text{Si}\left(111\right)\text{−}4\times 1$ surface at 300 K. The Na coverage for (d) was 0.007 ML. The slices were taken along the $\overline{\Gamma }\text{−}\overline{X}$ line of the surface Brillouin zone in (b). The photoelectron intensity is given in a gray scale with darker contrast for higher intensity. (e) and (f) show momentum distribution curves of the ARPES intensity at Fermi energy $\left(E_F\right)$ and the amount of the doped electrons estimated from the peak positions of these curves. The line in (f) is linear fit of the plot.Reuse & Permissions

Figure 2

(Color online) (a) An empty-state STM image of the In/Si(111) surface with 0.002 ML of Na at 110 K taken at the sample bias (tunneling current) of 0.3 V (20 pA). The inset shows the close-up image of the $4\times 1$ domain $\left(-0.3\text{V}\right)$. (b) An enlarged images of the same surface showing the phase fluctuation. The circled areas exhibit the local $\times 2$ distortions induced by Na adsorbates (bright protrusions). Closeups of the (c) $8\times 2$ and (d) Na-induced $4\times 2$ parts in the filled state $\left(-1.0\text{V}\right)$ taken at 77 K. The corresponding local unit cells are depicted.Reuse & Permissions

Figure 3

(Color online) Evidences for the suppression of the phase transition on Na-deposited $\text{Si}\left(111\right)4\times 1\text{-In}$ surfaces. (a) and (c) show temperature dependence of the area fraction of $4\times 1$, $8\times 2$, and $4\times 2$ phases, and the intensity of the $\times 8$ spot in LEED, respectively, for the pristine and Na-deposited $\text{Si}\left(111\right)4\times 1\text{-In}$ surfaces. As shown in (b), LEED shows the $4\times 1$ periodicity represented by the rectangle down to 53 K for the highly doped surfaces. The $\times 8$ spots and $\times 2$ streak, which are indicated by the arrowheads in (b), appear on the pristine surface below 120 K.Reuse & Permissions

Figure 4

(Color online) (a) The same surface as in Figs. 2a, 2b taken at 77 K and 0.5 V (60 pA). (b) enlarges the area enclosed with the square in (a). (c) STS $I\text{−}V$ curves taken on the points 1–15 in (b). Horizontal lines are put on several curves to feature the slope at the zero bias.Reuse & Permissions

Figure 5

(Color online) (a), (b) Successive STM images (with a 25 min interval) showing the phase fluctuation (within the ellipse) on the In/Si(111) surface with 0.05 ML of Na at 77 K. The tunneling condition was $-0.3\text{V}$ (70 pA). (c) An STM image (0.3 V, 50 pA) of the surface with 0.002 ML Na at 130 K and (d) STS $I\text{−}V$ curves taken on the Na-induced $4\times 2\left(A\right)$ and pristine $4\times 1\left(B\right)$ parts.Reuse & Permissions