Ground-state phase diagram of the one-dimensional dimerized t-J model at quarter filling

TL;DR

This paper investigates the ground-state phase diagram of a one-dimensional dimerized t-J model at quarter filling, revealing how different dimerizations influence various quantum phases using exact diagonalization.

Contribution

It provides the first comprehensive phase diagram of the dimerized t-J model at quarter filling, highlighting the competing effects of hopping and exchange dimerizations.

Findings

Identification of multiple quantum phases including Mott insulator, TLL, and Luther-Emery-liquid.

Demonstration of the competing roles of hopping and exchange dimerizations.

Mapping of the phase diagram across different dimerization parameters.

Abstract

The ground state of the one-dimensional dimerized $t$$-$$J$ model at quarter filling is studied by a Lanczos exact-diagonalization technique on small clusters. We calculate the charge gap, spin gap, binding energy, Tomonaga-Luttinger-liquid parameter, Drude weight, anomalous flux quantization, etc. We thereby show that the two types of dimerization, i.e., a dimerization of hopping integral and a dimerization of exchange interaction play a mutually competing role in controlling the ground state of the system and this leads to the emergence of various phases including the Mott insulating, Tomonaga-Luttinger-liquid, and Luther-Emery-liquid phases. The ground-state phase diagram of the model is given on the parameter space of the dimerizations.