Role of electron-electron interactions in $M$-valley twisted transition metal dichalcogenides

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Hauptverfasser: De Beule, Christophe, Peng, Liangtao, Mele, E. J., Adam, Shaffique
Format: Preprint
Veröffentlicht: 2025
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author De Beule, Christophe
Peng, Liangtao
Mele, E. J.
Adam, Shaffique
author_facet De Beule, Christophe
Peng, Liangtao
Mele, E. J.
Adam, Shaffique
contents We investigate the role of long-range Coulomb interactions in $M$-valley moirés using the self-consistent Hartree-Fock approximation. This platform was recently proposed [Nature 643, 376 (2025) and arXiv:2411.18828 (2024)] as a new class of experimentally realizable moiré materials using twisted transition metal dichalcogenides homobilayers with the 1T structure. While these seminal studies considered the noninteracting theory without an electric displacement field, this work shows that both electron-electron interactions at finite doping and an interlayer bias strongly modify the moiré bands. For small twists ($\lesssim 5^\circ$) the density of states versus filling and interlayer bias displays qualitatively different behavior for twisting near aligned ($0^\circ$) and antialigned ($60^\circ$) stacking with tunable Van Hove singularities (VHSs). Moreover, interactions pin the VHS to the Fermi energy over a finite range of doping both at zero and finite bias depending on the stacking type, an effect known to enhance both superconductivity and strongly correlated states. At half filling, we obtain the phase diagram as a function of interaction strength, interlayer bias, and twist angle. We find a competition driven by band mixing between an isotropic ferromagnet and an antiferromagnet that are nearly degenerate over a wide range of experimentally accessible parameters. Our work demonstrates that correlated states in $M$-valley 1T tTMDs can be strongly tuned in situ both by applying an electric displacement field and by electron doping.
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id arxiv_https___arxiv_org_abs_2508_14283
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Role of electron-electron interactions in $M$-valley twisted transition metal dichalcogenides
De Beule, Christophe
Peng, Liangtao
Mele, E. J.
Adam, Shaffique
Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
We investigate the role of long-range Coulomb interactions in $M$-valley moirés using the self-consistent Hartree-Fock approximation. This platform was recently proposed [Nature 643, 376 (2025) and arXiv:2411.18828 (2024)] as a new class of experimentally realizable moiré materials using twisted transition metal dichalcogenides homobilayers with the 1T structure. While these seminal studies considered the noninteracting theory without an electric displacement field, this work shows that both electron-electron interactions at finite doping and an interlayer bias strongly modify the moiré bands. For small twists ($\lesssim 5^\circ$) the density of states versus filling and interlayer bias displays qualitatively different behavior for twisting near aligned ($0^\circ$) and antialigned ($60^\circ$) stacking with tunable Van Hove singularities (VHSs). Moreover, interactions pin the VHS to the Fermi energy over a finite range of doping both at zero and finite bias depending on the stacking type, an effect known to enhance both superconductivity and strongly correlated states. At half filling, we obtain the phase diagram as a function of interaction strength, interlayer bias, and twist angle. We find a competition driven by band mixing between an isotropic ferromagnet and an antiferromagnet that are nearly degenerate over a wide range of experimentally accessible parameters. Our work demonstrates that correlated states in $M$-valley 1T tTMDs can be strongly tuned in situ both by applying an electric displacement field and by electron doping.
title Role of electron-electron interactions in $M$-valley twisted transition metal dichalcogenides
topic Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
url https://arxiv.org/abs/2508.14283