Kondo effect and its destruction in hetero-bilayer transition metal dichalcogenides

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Xie, Fang, Chen, Lei, Si, Qimiao
Format: Preprint
Publié: 2023
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866910870667264000
author Xie, Fang
Chen, Lei
Si, Qimiao
author_facet Xie, Fang
Chen, Lei
Si, Qimiao
contents Moiré structures, along with line-graph-based $d$-electron systems, represent a setting to realize flat bands. One form of the associated strong correlation physics is the Kondo effect. Here, we address the recently observed Kondo-driven heavy fermion state and its destruction in AB-stacked hetero-bilayer transition metal dichalcogenides, which can be controlled by the gate voltages. By studying an effective interacting Hamiltonian using the slave spin approach, we obtained a phase diagram with the total filling factor and the displacement field strength as the tunable parameters. In an extended range of the tunable displacement field, our numerical results show that the relative filling of the $d$ orbital, which is associated with the highest moiré band from the $\rm MoTe_2$ layer, is enforced to be $ν_d \approx 1$ by the interaction. This agrees with the experimental observation. We also argue that the observed high coherence temperature scale could be explained by the non-negligible bandwidth of the $d$ orbital. Our results set the stage to address the amplified quantum fluctuations that the Kondo effect may produce in these structures and new regimes that the systems open up for Kondo-destruction quantum criticality.
format Preprint
id arxiv_https___arxiv_org_abs_2310_20676
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Kondo effect and its destruction in hetero-bilayer transition metal dichalcogenides
Xie, Fang
Chen, Lei
Si, Qimiao
Strongly Correlated Electrons
Moiré structures, along with line-graph-based $d$-electron systems, represent a setting to realize flat bands. One form of the associated strong correlation physics is the Kondo effect. Here, we address the recently observed Kondo-driven heavy fermion state and its destruction in AB-stacked hetero-bilayer transition metal dichalcogenides, which can be controlled by the gate voltages. By studying an effective interacting Hamiltonian using the slave spin approach, we obtained a phase diagram with the total filling factor and the displacement field strength as the tunable parameters. In an extended range of the tunable displacement field, our numerical results show that the relative filling of the $d$ orbital, which is associated with the highest moiré band from the $\rm MoTe_2$ layer, is enforced to be $ν_d \approx 1$ by the interaction. This agrees with the experimental observation. We also argue that the observed high coherence temperature scale could be explained by the non-negligible bandwidth of the $d$ orbital. Our results set the stage to address the amplified quantum fluctuations that the Kondo effect may produce in these structures and new regimes that the systems open up for Kondo-destruction quantum criticality.
title Kondo effect and its destruction in hetero-bilayer transition metal dichalcogenides
topic Strongly Correlated Electrons
url https://arxiv.org/abs/2310.20676