QuasiFermi liquid behavior in a onedimensional system of interacting spinless fermions
Abstract
We present numerical evidence for a paradigm in onedimensional interacting fermion systems, whose phenomenology has traits of both Luttinger liquids and Fermi liquids. This state, dubbed a quasiFermi liquid, possesses a discontinuity in its fermion occupation number at the Fermi momentum. The excitation spectrum presents particlelike quasiparticles and absence of holelike quasiparticles, giving rise instead to edge singularities. Such a state is realized in a onedimensional spinless fermion lattice Hamiltonian by finetuning the interactions to a regime where they become irrelevant in the renormalization group sense. We show, using uniform infinite matrix products states and finiteentanglement scaling analysis, that the system ground state is characterized by a Luttinger parameter K =1 and a discontinuous jump in the fermion occupation number. We support the characterization with calculations of the spectral function that show a particlehole asymmetry reflected in the existence of welldefined Landau quasiparticles above the Fermi level and edge singularities without the associated quasiparticles below. These results indicate that the quasiFermi liquid paradigm can be realized beyond the lowenergy perturbative realm.
 Publication:

Physical Review B
 Pub Date:
 December 2023
 DOI:
 10.1103/PhysRevB.108.245134
 arXiv:
 arXiv:2305.13374
 Bibcode:
 2023PhRvB.108x5134B
 Keywords:

 Condensed Matter  Strongly Correlated Electrons;
 Condensed Matter  Materials Science;
 Condensed Matter  Statistical Mechanics
 EPrint:
 10+3 pages