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  • Letter
  • Open Access

Linear and nonlinear optical responses in Kitaev spin liquids

Minoru Kanega1,*, Tatsuhiko N. Ikeda2,†, and Masahiro Sato1,‡

  • 1Department of Physics, Ibaraki University, Mito, Ibaraki 310-8512, Japan
  • 2Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan

  • *20nm010t@vc.ibaraki.ac.jp
  • †tikeda@issp.u-tokyo.ac.jp
  • ‡masahiro.sato.phys@vc.ibaraki.ac.jp
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Phys. Rev. Research 3, L032024 – Published 28 July, 2021

DOI: https://doi.org/10.1103/PhysRevResearch.3.L032024

Abstract

We theoretically study THz-light-driven high-harmonic generation (HHG) in the spin-liquid states of the Kitaev honeycomb model with a magnetostriction coupling between spin and electric polarization. To compute the HHG spectra, we numerically solve the Lindblad equation, taking account of the dissipation effect. We find that isotropic Kitaev models possess a dynamical symmetry, which is broken by a static electric field, analogous to HHG in electron systems. We show that the HHG spectra exhibit characteristic continua of Majorana fermion excitations, and their broad peaks can be controlled by applying static electric or magnetic fields. In particular, the magnetic-field dependence of the HHG spectra drastically differs from those of usual ordered magnets. These results indicate that an intense THz laser provides a powerful tool to observe dynamic features of quantum spin liquids.

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Phys. Rev. Research 3, L032024– Published 28 July, 2021
  • Received 15 January 2021
  • Accepted 8 July 2021
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