Figure 1

(Color online) ${\text{ErTe}}_3$ FS determined from ARPES. Data taken at $T=10\text{K}$ with $h\nu =23.5\text{eV}$ and a 10 meV integration window around $E_F$. Solid square outlines first BZ of the true 3D crystal structure. Dashed lines are expected FS from 2D Te net unmodulated by CDWs. Red dotted square outlines FS areas shown in Fig. 3.Reuse & Permissions

Figure 2

(Color online) (a) ARPES FS (top) compared to interacting TB model FS (bottom) with either one (left) or two (right) CDWs. Both the data and model use a logarithmic intensity scale and 20 meV integration window about $E_F$ to emphasize weaker features. The TB model was convoluted with an angular resolution function. Vertical dotted line distinguishes between TB model with one or two CDWs. (b) Energy of LEG in the dispersion relative to $E_F$ measured along the inner FS for a constant $k_z$. Note the CDW gap magnitude is measured relative to the center of the gap (see Fig. 3). The markers are the data and the lines are from the TB model. Shaded areas correspond to regions where entire CDW gap is below $E_F$ resulting in intensity at $E_F$ (see text). (c) Density of states from the TB model with different number of CDWs present.Reuse & Permissions

Figure 3

(Color online) [(a)–(c)] ${\text{ErTe}}_3$ Fermi surface taken at different temperatures. The data show one section of the inner FS to emphasize the effects of the closing gaps. Markers correspond to locations of the measured gaps. Horizontal lines in (a) represent extent of cuts shown in (d) and (e). [(d) and (e)] Spectra divided by the Fermi function at different temperatures for the large and small gaps, respectively. The black dashed line emphasizes $E_F$ while the red dotted line emphasizes the center of the closing gaps. [(f) and (g)] Temperature dependence of the fitted and denoised dispersion data for the large and small gaps, respectively. Different colored lines correspond to different temperatures. Dashed vertical lines mark the center of the closing gaps. (h) Summary of the two energy gaps for different temperatures. Solid lines show expected mean-field behavior with energy gaps and transition temperatures scaled to experimental values. Note that the magnitude of each gap is measured from the center of each gap marked by horizontal dashed lines.Reuse & Permissions