2017/03/30 by Joji Nasu, Junki Yoshitake, Yukitoshi Motome · 3 citations
Physics and Astronomy · #Advanced Condensed Matter Physics #Condensed matter physics #Electron #Ferromagnetism #Fractionalization #Ground state #Magnon #Phonon #Physics #Physics of Superconductivity and Magnetism #Quantum #Quantum mechanics #Quantum spin liquid #Quasiparticle #Spin (aerodynamics) #Spin polarization #Spins #Superconductivity #Thermal conductivity #Thermodynamics #Topological Materials and Phenomena #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.119.127204
published as Phys. Rev. Lett. 119, 127204 (2017) · 5 pages, 3 figures
arxiv created 2017/03/30 · openalex publication_date 2017/09/22 · arxiv updated 2017/09/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
In conventional insulating magnets, heat is carried by magnons and phonons. In contrast, when the magnets harbor a quantum spin liquid state, emergent quasiparticles from the fractionalization of quantum spins can carry heat. Here, we investigate unconventional thermal transport yielded by such exotic carriers, in both longitudinal and transverse components, for the Kitaev model, whose ground state is exactly shown to be a quantum spin liquid with fractional excitations described as itinerant Majorana fermions and localized Z2 fluxes. We find that the longitudinal thermal conductivity exhibits a single peak at a high temperature, while the nonzero frequency component has a peak at a low temperature, reflecting the spin fractionalization. On the other hand, we show that the transverse thermal conductivity is induced by the magnetic field in a wide temperature range up to the energy scale of the bare exchange coupling; while increasing temperature, the transverse response divided by temperature decreases from the quantized value expected for the topologically nontrivial ground state and shows nonmonotonic temperature dependence. These characteristic behaviors provide experimentally accessible evidence of fractional excitations in the proximity to the Kitaev quantum spin liquid.