Photoinduced enhancement of bond-order in the one-dimensional extended Hubbard model

Using the time-dependent Lanczos technique, we investigate the short-time evolution of the half-filled one-dimensional extended Hubbard model in the strong-coupling regime, when driven by a transient laser pulse. Starting from a phase displaying charge-density wave (CDW), a steady photoinduced in-gap state in the optical conductivity is found, depending on the parameters of the laser pulse. This potentially describes similar results of a recent experiment using organic salts [Nat. Phys. 7, 114 (2011)], also subjected to external drivings. On top of that, we parametrize the conditions of the pulse so as to maximize the overlap of the time-evolving wavefunction with excited states displaying the elusive bond-ordered wave of this model, with the focus on providing a protocol to experiments for its observation. Further, we try to make a connection between the emergence of this order and the formation of the aforementioned in-gap state, comparing with different types of excitations on the ground state.