Fig. 2: Temperature dependence of CDW state in monolayer 1T-ZrTe₂.

a Atomically resolved STM images of 10 nm × 10 nm and corresponding FFT images at 4.5 K [V_bias = −50 mV, I = 200 pA], 77 K [V_bias = 50 mV, I = 250 pA], 116 K [V_bias = −150 mV, I = 280 pA] and 300 K [V_bias = −100 mV, I = 300 pA]. b The band structures measured along the experimental Γ-M direction at 14, 120, and 300 K. c EDCs measured exactly at M/Γ* (correspond to red dashed lines in (b), as a function of temperature. Three peaks are clearly recognized in the spectra measured at T = 50 K, corresponding to one conduction band and two folded valence bands, respectively. d The evolutions of the size of the bandgap, the intensity of the folded second valence band, and 2 × 2 superlattice peaks in STM with temperature. At the high-temperature region, it is hard to tell whether the folded first valence band merges into the conduction band or disappears. Different fitting strategies (circles with different colors, Supplementary Fig. 2) are employed, and the results show an identical trend. The error bars indicate the standard error of the fit coherence times.