Figure 1
From: Super-resolved time–frequency measurements of coupled phonon dynamics in a 2D quantum material
(a) Crystal structure of 1T-TaSe2 formed by Se-Ta-Se sandwiched layers; blue = Ta, yellow = Se. (b) Cartoon of the 2D CDW in 1T-TaSe2; grey dots represent the Ta atoms (atomic displacements exaggerated) while blue represents electron density (dark blue corresponding to high electron density). (c) Transient reflectivity of TaSe2 taken with high (orange) and low (blue) pump fluences. Electron excitation and relaxation are responsible for the fast rise and decay; coherent phonons are observed as an oscillating signal, and the long-lived, negative-going component comes from the change in the refractive index due to heating (incoherent phonons). Inset: the same data but only the first 5 ps are shown.
