Anomalous Spin and Charge Dynamics of the 2D t-J Model at low doping

TL;DR

This study uses exact diagonalization to analyze the dynamical spin and charge correlations in the 2D t-J model at low doping, revealing distinct scaling behaviors and supporting the spin bag picture.

Contribution

It provides a detailed analysis of spin and charge dynamics in the 2D t-J model, highlighting their different behaviors and explaining them through the spin bag concept.

Findings

Density correlations resemble bosonic behavior of doped holes.

Spin correlations are consistent with fermionic behavior in a narrow band.

Distinct scaling laws for spin and charge correlations at low doping.

Abstract

We present an exact diagonalization study of the dynamical spin and density correlation function of the 2D t-J model for hole doping < 25%. Both correlation functions show a remarkably regular, but completely different scaling behaviour with both hole concentration and parameter values: the density correlation function is consistent with that of bosons corresponding to the doped holes and condensed into the lowest state of the noninteracting band of width 8t, the spin correlation function is consistent with Fermions in a band of width J. We show that the spin bag picture gives a natural explanation for this unusual behaviour.