Probing strongly correlated electron dynamics on extreme timescales

We use sub-10 fs laser pulses in the visible and near IR region of the spectrum in order to probe the dynamics of photo-induced phase transitions on their characteristic timescales. We present results from two different cases: the 1D organic Mott insulator ET-F₂TCNQ and the more complex, colossal magneto-resistive manganite, Pr_0.7Ca_0.3MnO₃. For the former, we find that the melting of the Mott state takes 20 fs, a timescale which is dictated by the electron tunnelling time, h/t. In comparison, the dynamics of the manganite show coupling to a 14 THz structural mode and a high frequency 30 THz mode, which we assign as an orbiton, a collective electronic excitation.