Multiferroicity and Topology in Twisted Transition Metal Dichalcogenides

Fuente: arXiv
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Autori principali: Abouelkomsan, Ahmed, Bergholtz, Emil J., Chatterjee, Shubhayu
Natura: Preprint
Pubblicazione: 2022
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author Abouelkomsan, Ahmed
Bergholtz, Emil J.
Chatterjee, Shubhayu
author_facet Abouelkomsan, Ahmed
Bergholtz, Emil J.
Chatterjee, Shubhayu
contents Van der Waals heterostructures have recently emerged as an exciting platform for investigating the effects of strong electronic correlations, including various forms of magnetic or electrical orders. Here, we perform an unbiased exact diagonalization study of the effects of interactions on topological flat bands of twisted transition metal dichalcogenides (TMDs) at odd integer fillings. For hole-filling $ν_h = 1$, we find that Chern insulator phases, expected from interaction-induced spin-valley polarization of the bare bands, are quite fragile, and give way to spontaneous multiferroic order -- coexisting ferroelectricity and ferromagnetism, in presence of long-range Coulomb repulsion. We provide a simple real-space picture to understand the phase diagram as a function of interaction range and strength. Our findings establish twisted TMDs as a novel and highly tunable platform for multiferroicity, and we outline a potential route towards electrical control of magnetism in the multiferroic phase.
format Preprint
id arxiv_https___arxiv_org_abs_2210_14918
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Multiferroicity and Topology in Twisted Transition Metal Dichalcogenides
Abouelkomsan, Ahmed
Bergholtz, Emil J.
Chatterjee, Shubhayu
Strongly Correlated Electrons
Mesoscale and Nanoscale Physics
Materials Science
Van der Waals heterostructures have recently emerged as an exciting platform for investigating the effects of strong electronic correlations, including various forms of magnetic or electrical orders. Here, we perform an unbiased exact diagonalization study of the effects of interactions on topological flat bands of twisted transition metal dichalcogenides (TMDs) at odd integer fillings. For hole-filling $ν_h = 1$, we find that Chern insulator phases, expected from interaction-induced spin-valley polarization of the bare bands, are quite fragile, and give way to spontaneous multiferroic order -- coexisting ferroelectricity and ferromagnetism, in presence of long-range Coulomb repulsion. We provide a simple real-space picture to understand the phase diagram as a function of interaction range and strength. Our findings establish twisted TMDs as a novel and highly tunable platform for multiferroicity, and we outline a potential route towards electrical control of magnetism in the multiferroic phase.
title Multiferroicity and Topology in Twisted Transition Metal Dichalcogenides
topic Strongly Correlated Electrons
Mesoscale and Nanoscale Physics
Materials Science
url https://arxiv.org/abs/2210.14918