Quantum quench for inhomogeneous states in the nonlocal Luttinger model

In the Luttinger model with nonlocal interaction we investigate, by exact analytical methods, the time evolution of an inhomogeneous state with a localized fermion added to the noninteracting ground state. In the absence of interaction the averaged density has two peaks moving in opposite directions with constant velocities. If the state is evolved with the interacting Hamiltonian, two main effects appear. The first is that the peaks have velocities which are not constant but vary between a minimal and maximal value. The second is that a dynamical "Landau quasiparticle weight" appears in the oscillating part of the averaged density, asymptotically vanishing with time, as a consequence of the fact that fermions are not excitations of the interacting Hamiltonian.