Real Time Dynamics of Hole Propagation in Strongly Correlated Conjugated Molecular Chains: A time-dependent DMRG Study

TL;DR

This study uses time-dependent DMRG to investigate how electron-electron interactions influence spin and charge transport velocities in conjugated polymer chains, revealing that correlations slow spin but not charge movement.

Contribution

It applies the time-dependent DMRG method to analyze spin and charge dynamics in correlated one-dimensional systems modeled by the Hubbard model, highlighting the differential impact of interactions.

Findings

Charge and spin velocities differ with correlations.

Interactions slow down spin velocity.

Dimerization has minimal effect on velocities.

Abstract

In this paper, we address the role of electron-electron interactions on the velocities of spin and charge transport in one-dimensional systems typified by conjugated polymers. We employ the Hubbard model to model electron-electron interactions. The recently developed technique of time dependent Density Matrix Renormalization Group (tdDMRG) is used to follow the spin and charge evolution in an initial wavepacket described by a hole doped in the ground state of the neutral system. We find that the charge and spin velocities are different in the presence of correlations and are in accordance with results from earlier studies; the charge and spin move together in the noninteracting picture while interaction slows down only the spin velocity. We also note that dimerization of the chain only weakly affects these velocities.