Ultrafast melting of charge-density wave fluctuations at room temperature in 1T-TiSe2 monitored under non-equilibrium conditions

We investigate the ultrafast lattice dynamics in 1T-TiSe2 using femtosecond reflection pump–probe and pump–pump–probe techniques at room temperature. The time-domain signals Fourier-transformed spectra show A1g phonon mode 5.9 THz. Moreover, we observe an additional ≈ 3 THz, corresponding to charge-density wave (CDW) amplitude (AM), which is generally visible below Tc≈200 K. argue that emergence of CDW temperature can be a consequence fluctuations order parameters based on experiment technique, exhibited suppression AM signal within timescale ∼0.5 ps.