Ultrafast Response Of Plasmalike Reflectivity Edge In (Tmttf)(2)Asf6 Driven By A 7-Fs 1.5-Cycle Strong-Light Field

The strong-light field effect of (TMTTF)(2)AsF6 was investigated utilizing 1.5-cycle, 7-fs infrared pulses. The ultrafast (similar to 20 fs) and large (similar to 40%) response of the plasmalike reflectivity edge (similar to 0.7 eV) was analyzed by the changes in omega(p) = root ne(2)/(epsilon(infinity)epsilon(0)m) (n: number of charges in the 1/4-filled band; m: mass of charge; epsilon(infinity), epsilon(0): dielectric constants for high frequency and vacuum; e: elementary charge). The 3% reduction in omega(p) is attributed to the 6% increase in m. Furthermore, 20 fs oscillation of omega(p) in the time domain indicates that the plasmalike edge is affected by the charge gap (similar to 0.2 eV) nature. Theoretical calculations suggest that the Coulomb repulsion plays an important role in the increase in m.