Fig. 3: The two-step process of the CDW formation in monolayer 1T-ZrTe2.
From: Signatures of the exciton gas phase and its condensation in monolayer 1T-ZrTe2
a, c The band structures measured by ARPES along the Γ-M direction at 15 K (a) and 300 K (c) using 50.6 eV synchrotron radiation light. e ARPES data along the Γ-M direction taken from surface K-doped sample with a carrier density of 0.14 e−/Zr atom. The corresponding EDCs are shown in (b, d, f) respectively. g ARPES snapshots taken before optical pumping and at characteristic pump-probe delays at the Γ point. h MDCs for the data shown in (g). i, j Band position (bands are shifted by aligning the second valence band to 15 K data for comparison) (i) and spectral weight (normalized by dividing by the maximum spectral weight) (j) of the first valence band at the Γ point along Γ-M direction. There is no apparent difference in the band dispersions and SW of the first valence band between the CDW (15 K) state and the normal state (300 K). In contrast, the interaction-suppressed state (photo-excited and K-doped) shows considerable band renormalization and SW recovery, respectively.
