Topological Kondo semimetals emulated in hetero-bilayer transition metal dichalcogenides

Fuente: arXiv
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Auteurs principaux: Xie, Fang, Chen, Lei, Fang, Yuan, Si, Qimiao
Format: Preprint
Publié: 2024
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_version_ 1866915483488354304
author Xie, Fang
Chen, Lei
Fang, Yuan
Si, Qimiao
author_facet Xie, Fang
Chen, Lei
Fang, Yuan
Si, Qimiao
contents The moiré structure of AB-stacked $\rm{MoTe_2/WSe_2}$ represents a natural platform to realize Kondo lattice models, due to the discrepancy of the bandwidth between the individual layers. Here, we study this system at the commensurate filling of $ν_{\rm tot}=2$. Our focus is on the $1+1$ filling setting of $ν_{\rm Mo} =ν_{\rm W}=1$, which enables a Kondo lattice description. We find a Kondo semimetal due to the sizable intra-orbital hopping among the electrons in the $\rm{MoTe_2}$ layer. The Kondo-driven (emergent) flat band is naturally pinned to the Fermi energy. When combined with the inherent topology of the electronic structure, a topological Kondo semimetal phase ensues. We calculate the valley Hall response and, due to the breaking of inversion symmetry, also identify a spontaneous Hall effect. There is a Berry curvature dodecapole, which leads to a fourth-order spontaneous Hall effect in the perturbative regime of the electric field that is further amplified in the non-perturbative regime. As such, the system provides a tunable setting to simulate topological Kondo semimetals. Finally, we discuss the pathways that connect the physics realized here to the Weyl Kondo semimetals and their proximate phases that have been advanced in recent years in topological Kondo lattice models and materials.
format Preprint
id arxiv_https___arxiv_org_abs_2407_20182
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Topological Kondo semimetals emulated in hetero-bilayer transition metal dichalcogenides
Xie, Fang
Chen, Lei
Fang, Yuan
Si, Qimiao
Strongly Correlated Electrons
The moiré structure of AB-stacked $\rm{MoTe_2/WSe_2}$ represents a natural platform to realize Kondo lattice models, due to the discrepancy of the bandwidth between the individual layers. Here, we study this system at the commensurate filling of $ν_{\rm tot}=2$. Our focus is on the $1+1$ filling setting of $ν_{\rm Mo} =ν_{\rm W}=1$, which enables a Kondo lattice description. We find a Kondo semimetal due to the sizable intra-orbital hopping among the electrons in the $\rm{MoTe_2}$ layer. The Kondo-driven (emergent) flat band is naturally pinned to the Fermi energy. When combined with the inherent topology of the electronic structure, a topological Kondo semimetal phase ensues. We calculate the valley Hall response and, due to the breaking of inversion symmetry, also identify a spontaneous Hall effect. There is a Berry curvature dodecapole, which leads to a fourth-order spontaneous Hall effect in the perturbative regime of the electric field that is further amplified in the non-perturbative regime. As such, the system provides a tunable setting to simulate topological Kondo semimetals. Finally, we discuss the pathways that connect the physics realized here to the Weyl Kondo semimetals and their proximate phases that have been advanced in recent years in topological Kondo lattice models and materials.
title Topological Kondo semimetals emulated in hetero-bilayer transition metal dichalcogenides
topic Strongly Correlated Electrons
url https://arxiv.org/abs/2407.20182