Resolving geometric excitations of fractional quantum Hall states

The quantum dynamics of the intrinsic metric profoundly influence the neutral excitations in the fractional quantum Hall system, as established by Haldane [Phys. Rev. Lett. 107, 116801 (2011)], and further evidenced by a recent two-photon experiment [J. Liang et al., Nature (London) 628, 78 (2024)]. Despite these advancements, a comprehensive understanding of the dynamic properties of these excitations, especially at long wavelengths, continues to elude interest. In this study, we employ tensor-network methods to investigate the neutral excitations of the Laughlin and Moore-Read states on an infinite cylinder. This investigation deepens our understanding of the excitation spectrum in regions where traditional methods do not work effectively. The spectral functions for both states reveal the presence of $S=\ensuremath{-}2$ geometric excitations. We unveil the complex spectra of both neutral fermion and bosonic Girvin-MacDonald-Platzman modes within the excitation continuum by calculating the three-particle density response function for the Moore-Read state. Our findings support the hypothesis of emergent supersymmetry and highlight the potential for detecting neutral fermions in future experiments.