Figure 1 | Scientific Reports

Figure 1

From: Coherent surface-to-bulk vibrational coupling in the 2D topologically trivial insulator Bi2Se3 monitored by ultrafast transient absorption spectroscopy

Figure 1

TA spectra of the topologically trivial insulator phase of the 2D TI Bi2Se3. (a–e) Set of TA spectra of the 2 QL thick Bi2Se3 film measured at delay times indicated by the corresponding colors using the ∼ 340 nm pumping (∼ 3.65 eV photon energy) of different powers, as indicated for each of the columns. Part (a) and (b) show the same TA spectra for clarity. The zero-intensity lines of TA spectra in part (a) were shifted along the ΔOD axis (optical density change) for better observation. The factor (λprobe)2 in the ΔOD axis arises due to wavelength-to-energy units’ transformation. The low-energy edge of the transiently excited electron population (Eedge) is indicated in part (a).

Back to article page