Topological charge excitations and Green's function zeros in paramagnetic Mott insulators

Fuente: arXiv
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Main Authors: Pangburn, Emile, Pépin, Catherine, Banerjee, Anurag
Format: Preprint
Published: 2024
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author Pangburn, Emile
Pépin, Catherine
Banerjee, Anurag
author_facet Pangburn, Emile
Pépin, Catherine
Banerjee, Anurag
contents We investigate the emergence of topological features in the charge excitations of Mott insulators in the Chern-Hubbard model. In the strong correlation regime, treating electrons as the sum of holons and doublons excitations, we compute the topological phase diagram of Mott insulators at half-filling using composite operator formalism. The Green function zeros manifest as the tightly bound pairs of such elementary excitations of the Mott insulators. Our analysis examines the winding number associated with the occupied Hubbard bands and the band of Green's function zeros. We show that both the poles and zeros show gapless states and zeros, respectively, in line with bulk-boundary correspondence. The gapless edge states emerge in a junction geometry connecting a topological Mott band insulator and a topological Mott zeros phase. These include an edge electronic state that carries a charge and a charge-neutral gapless zero mode. Our study is relevant to several twisted materials with flat bands where interactions play a dominant role.
format Preprint
id arxiv_https___arxiv_org_abs_2412_13302
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Topological charge excitations and Green's function zeros in paramagnetic Mott insulators
Pangburn, Emile
Pépin, Catherine
Banerjee, Anurag
Strongly Correlated Electrons
We investigate the emergence of topological features in the charge excitations of Mott insulators in the Chern-Hubbard model. In the strong correlation regime, treating electrons as the sum of holons and doublons excitations, we compute the topological phase diagram of Mott insulators at half-filling using composite operator formalism. The Green function zeros manifest as the tightly bound pairs of such elementary excitations of the Mott insulators. Our analysis examines the winding number associated with the occupied Hubbard bands and the band of Green's function zeros. We show that both the poles and zeros show gapless states and zeros, respectively, in line with bulk-boundary correspondence. The gapless edge states emerge in a junction geometry connecting a topological Mott band insulator and a topological Mott zeros phase. These include an edge electronic state that carries a charge and a charge-neutral gapless zero mode. Our study is relevant to several twisted materials with flat bands where interactions play a dominant role.
title Topological charge excitations and Green's function zeros in paramagnetic Mott insulators
topic Strongly Correlated Electrons
url https://arxiv.org/abs/2412.13302