Dynamical Functions of a 1D Correlated Quantum Liquid

TL;DR

This paper extends the pseudofermion dynamical theory to zero spin density states in 1D correlated metals, providing detailed spectral function expressions that explain experimental photoemission features and are applicable to ultracold atomic systems.

Contribution

It introduces new spectral function expressions for zero spin density states in 1D correlated systems, including near half filling and singular border lines, enhancing understanding of experimental observations.

Findings

Spectral functions near singular border lines derived.

Application to TTF-TCNQ explains photoemission features.

Expressions applicable to ultracold fermionic atoms in optical lattices.

Abstract

We extend to initial ground states with zero spin density m = 0 the expressions provided by the pseudofermion dynamical theory (PDT) for the finite-energy one- and two-electron spectral-weight distributions of a one-dimensional (1D) correlated metal with on-site particle-particle repulsion. The spectral-function expressions derived in this paper were used in recent successful and detailed theoretical studies of the finite-energy singular features in photoemission of the organic compound tetrathiafulvalene-tetracyanoquinodimethane (TTF-TCNQ) metallic phase. Our studies take into account spectral contributions from types of microscopic processes that do not occur for finite values of the spin density. Expressions for the spectral functions in the vicinity of the singular border lines which also appear in the TTF- TCNQ spectral-weight distribution are derived. In addition, the PDT expressions are generalized for electronic densities in the vicinity of half filling. Further details on the processes involved in the applications to TTF-TCNQ are reported. Our results are useful for the further understanding of the unusual spectral properties observed in low-dimensional organic metals and also provide expressions for the one- and two-atom spectral functions of a correlated quantum system of ultracold fermionic atoms in a 1D optical lattice with on-site two-atom repulsion.