Chiral Graviton Modes in Fermionic Fractional Chern Insulators

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Hauptverfasser: Long, Min, Bacciconi, Zeno, Lu, Hongyu, Xavier, Hernan B., Meng, Zi Yang, Dalmonte, Marcello
Format: Preprint
Veröffentlicht: 2026
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author Long, Min
Bacciconi, Zeno
Lu, Hongyu
Xavier, Hernan B.
Meng, Zi Yang
Dalmonte, Marcello
author_facet Long, Min
Bacciconi, Zeno
Lu, Hongyu
Xavier, Hernan B.
Meng, Zi Yang
Dalmonte, Marcello
contents Chiral graviton modes are hallmark collective excitations of Fractional Quantum Hall (FQH) liquids. However, their existence on the lattice, where continuum symmetries that protect them from decay are lost, is still an open and urgent question, especially considering the recent advances in the realization of Fractional Chern Insulators (FCI) in transition metal dichalcogenides and rhombohedral pentalayer graphene. Here we present a comprehensive theoretical and numerical study of graviton-modes in fermionic FCI, and thoroughly demonstrate their existence. We first derive a lattice stress tensor operator in the context of the fermionic Harper-Hofstadter(HH) model which captures the graviton in the flat band limit. Importantly, we discover that such lattice stress-tensor operators are deeply connected to lattice quadrupolar density correlators, readily generalizable to generic Chern bands. We then explicitly show the adiabatic connection between FQH and FCI chiral graviton modes by interpolating from a low flux HH model to a Checkerboard lattice model that hosts a topological flat band. In particular, using state-of-the-art matrix product state and exact diagonalization simulations, we provide strong evidence that chiral graviton modes are long-lived excitations in FCIs despite the lack of continuous symmetries and the scattering with a two-magnetoroton continuum. By means of a careful finite-size analysis, we show that the lattice generates a finite but small intrinsic decay rate for the graviton mode. We discuss the relevance of our results for the exploration of graviton modes in FCI phases realized in solid state settings, as well as cold atom experiments.
format Preprint
id arxiv_https___arxiv_org_abs_2601_05196
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Chiral Graviton Modes in Fermionic Fractional Chern Insulators
Long, Min
Bacciconi, Zeno
Lu, Hongyu
Xavier, Hernan B.
Meng, Zi Yang
Dalmonte, Marcello
Strongly Correlated Electrons
Quantum Physics
Chiral graviton modes are hallmark collective excitations of Fractional Quantum Hall (FQH) liquids. However, their existence on the lattice, where continuum symmetries that protect them from decay are lost, is still an open and urgent question, especially considering the recent advances in the realization of Fractional Chern Insulators (FCI) in transition metal dichalcogenides and rhombohedral pentalayer graphene. Here we present a comprehensive theoretical and numerical study of graviton-modes in fermionic FCI, and thoroughly demonstrate their existence. We first derive a lattice stress tensor operator in the context of the fermionic Harper-Hofstadter(HH) model which captures the graviton in the flat band limit. Importantly, we discover that such lattice stress-tensor operators are deeply connected to lattice quadrupolar density correlators, readily generalizable to generic Chern bands. We then explicitly show the adiabatic connection between FQH and FCI chiral graviton modes by interpolating from a low flux HH model to a Checkerboard lattice model that hosts a topological flat band. In particular, using state-of-the-art matrix product state and exact diagonalization simulations, we provide strong evidence that chiral graviton modes are long-lived excitations in FCIs despite the lack of continuous symmetries and the scattering with a two-magnetoroton continuum. By means of a careful finite-size analysis, we show that the lattice generates a finite but small intrinsic decay rate for the graviton mode. We discuss the relevance of our results for the exploration of graviton modes in FCI phases realized in solid state settings, as well as cold atom experiments.
title Chiral Graviton Modes in Fermionic Fractional Chern Insulators
topic Strongly Correlated Electrons
Quantum Physics
url https://arxiv.org/abs/2601.05196