Strong correlation induced charge localization in antiferromagnets

TL;DR

This study reveals that in antiferromagnetic Mott insulators, a doped hole becomes self-localized due to strong correlation effects, challenging traditional quasiparticle models and highlighting a new paradigm for understanding doped Mott insulators.

Contribution

The paper demonstrates, through DMRG simulations, that charge localization in doped Mott insulators arises from quantum interference of strong correlations, not disorder, and shows spin-charge separation persists.

Findings

Charge of doped hole is self-localized by correlation-induced quantum interference.

Spin of the doped hole remains mobile despite charge localization.

Challenges the quasiparticle picture in doped Mott insulators.

Abstract

The fate of an injected hole in a Mott antiferromagnet is an outstanding issue of strongly correlated physics. It provides important insights into doped Mott insulators closely related to high-temperature superconductivity in cuprates. Here, we report a systematic numerical study based on the density matrix renormalization group (DMRG). It reveals a remarkable novelty and surprise for the single hole's motion in otherwise well-understood Mott insulators. Specifically, we find that the charge of the hole is self-localized by a novel quantum interference mechanism purely of strong correlation origin, in contrast to Anderson localization due to disorders. The common belief of quasiparticle picture is invalidated by the charge localization concomitant with spin-charge separation: the spin of the doped hole is found to remain a mobile object. Our findings unveil a new paradigm for doped Mott insulators that emerges already in the simplest single hole case.