2021/03/31 by Shang-Shun Zhang, Gábor B. Halász, Wei Zhu +1
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Antiferromagnetism #Bound state #Condensation #Condensed matter physics #Excitation #Ferromagnetism #Heisenberg model #Magnetic and transport properties of perovskites and related materials #Phase (matter) #Phase transition #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Quantum spin liquid #Spin (aerodynamics) #Spin model #Spin polarization #Structure factor #Thermodynamics #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.104.014411
published as Phys. Rev. B 104, 014411 (2021) · 20 pages, 11 figures
openalex publication_date 2021/07/09 · arxiv created 2021/07/16 · arxiv updated 2021/07/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We compute the low-energy excitation spectrum and the dynamical spin structure factor of the Kitaev-Heisenberg-Gamma model through a variational approach based on the exact fractionalized excitations of the pure Kitaev honeycomb model. This novel approach reveals the physical reason for the asymmetric stability of the Kitaev spin liquid phases around the ferromagnetic and antiferromagnetic Kitaev limits. Moreover, we demonstrate that the fractionalized excitations form bound states in specific regions of each Kitaev spin liquid phase and that certain phase transitions induced by Heisenberg and Gamma interactions are driven by the condensation of such a bound state. Remarkably, this bound state appears as a sharp mode in the dynamical spin structure factor, while its condensation patterns at the appropriate phase transitions provide a simple explanation for the magnetically ordered phases surrounding each Kitaev spin liquid phase.