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arXiv:2207.03141 · Communications Physics

Exciton-assisted low-energy magnetic excitations in a photoexcited Mott insulator on a square lattice

Kenji Tsutsui, Kazuya Shinjo, Shigetoshi Sota, Takami Tohyama

Published Mar 5, 2023• 2 citations
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Abstract

Abstract Photoexcitation of a Mott insulator on a square lattice has weakened the intensity of both single- and two-magnon as observed in time-resolved resonant-inelastic x-ray scattering and time-resolved Raman scattering. However, the spectral change in low-energy regions below the magnons has not been clarified so far. To uncover the nature of photoinduced low-energy magnetic excitations of the Mott insulator, we numerically investigate transient magnetic dynamics in a photoexcited half-filled Hubbard model on the square lattice. After turning off a pump pulse tuned for an absorption edge, new magnetic signals clearly emerge well below magnon energy in both single- and two-magnon excitations. We find that the low-energy excitations are predominantly created via excitonic states at the absorption edge. These exciton-assisted magnetic excitations may provide a possible explanation for low-energy spectral weight in a recent time-resolved two-magnon Raman scattering experiment for insulating YBa2Cu3O6.1.

DOI
10.1038/s42005-023-01158-4

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