Numerical renormalization group study of the 1D t-J model

TL;DR

This paper applies an extended density matrix renormalization group method to the 1D t-J model, revealing how electron correlations and anomalies evolve with interaction strength and identifying a transition to an electron solid.

Contribution

It introduces a generalized DMRG method for arbitrary band filling and proves a theorem that accelerates computations, advancing numerical studies of the 1D t-J model.

Findings

Disappearance of the 3k_F anomaly with increasing J

Existence of a density-independent critical J_c for electron solid formation

Extended DMRG enables detailed analysis of correlation functions

Abstract

The one-dimensional (1D) $t-J$ model is investigated using the density matrix renormalization group (DMRG) method. We report for the first time a generalization of the DMRG method to the case of arbitrary band filling and prove a theorem with respect to the reduced density matrix that accelerates the numerical computation. Lastly, using the extended DMRG method, we present the ground state electron momentum distribution, spin and charge correlation functions. The $3k_F$ anomaly of the momentum distribution function first discussed by Ogata and Shiba is shown to disappear as $J$ increases. We also argue that there exists a density-independent $J_c$ beyond which the system becomes an electron solid.