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  • Letter
  • Open Access

Anomalous dispersion of shear waves in dipolar supersolids

P. Senarath Yapa* and T. Bland†

  • Universität Innsbruck, Fakultät für Mathematik, Informatik und Physik, Institut für Experimentalphysik, 6020 Innsbruck, Austria

  • *Contact author: pramodh.sy@gmail.com
  • †Contact author: thomas.bland1991@gmail.com
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Phys. Rev. A 112, L021303 – Published 22 August, 2025

DOI: https://doi.org/10.1103/xz57-52ft

Abstract

Dipolar supersolids—quantum states that are simultaneously superfluid and solid—have had their superfluid nature rigorously tested, while their solid nature remain uncharted. Arguably, the defining characteristic of a solid is the existence of elastic shear waves. In this work we investigate transverse wave packet propagation in dipolar supersolids with triangular and honeycomb structure. Remarkably, the honeycomb supersolid displays anomalous dispersion, supporting waves traveling faster than the transverse speed of sound. While the distinction between anomalous and normal dispersion appears subtle, it has a profound influence on both the transport and scattering properties. For both supersolid phases, we calculate the shear modulus, a key parameter that quantifies the material's rigidity. Our findings are pertinent to current experimental efforts scrutinizing the fundamental properties of supersolids.

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Phys. Rev. A 112, L021303– Published 22 August, 2025
  • Received 22 October 2024
  • Revised 1 May 2025
  • Accepted 5 August 2025
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