Dynamic Correlations of Quasi-Fermi Liquids

We present numerical calculations of the dynamic correlations characterizing a one-dimensional model that realizes quasi-Fermi liquid behavior. Quasi-Fermi liquids (qFL) were originally proposed as a new paradigm in one-dimensional interacting fermion systems, possessing characteristics of both Fermi liquids and Luttinger liquids. In this work, we compute the dynamic structure factor and spectral function in the thermodynamic limit using infinite matrix product states and tangent space methods. In the spectral function we show the presence of low-energy quasi-particles in both the particle and hole sector that also survive as one approaches the Fermi point. In the dynamic structure factor we find similarities to non-linear Luttinger Liquid physics with an extended continuum and high energy tails due to band curvature. The combined results offer a more completely characterization of the qFL paradigm in the context of 1D physics beyond the Tomonaga-Luttinger model.