Seminář ÚFKL: Juraj Rusnačko
29. září 2021
Semináře se konají v hale ÚFKL.
Ústav fyziky kondenzovaných látek vás zve na přednášku
Symmetries of the extended Kitaev model for relativistic transition-metal oxides
The field of Kitaev materials has been a very lively research area for a second decade now. The focal point of interest is how the hallmarks of Kitaev coupling -- quantum spin liquid ground state and bond-directional interactions -- arise in real materials through a subtle interplay of correlations and relativistic effects . The most widely applied minimal model is the extended Kitaev-Heisenberg model that is expected to be relevant for a large group of 3d, 4d and 5d transition metal compounds . In this talk I will present a relatively non-standard methodology of analyzing this model based on its symmetries . First, I will discuss how sublattice-dependent rotations uncover hidden points of SU(2) symmetry in the model. Second, I will show how a surprising cancellation of quantum fluctuations may arise in the bond-directional setting, leading to a continuous manifold of Ising-like classical states. Last, using a simple coordinate transformation, I will present a link to the continuum of single-axis "tripod" models. The talk will also detail how the symmetry analysis may aid in the construction of phasee diagrams or interpretation of experimental excitation spectra.
 G. Jackeli and G. Khaliullin, Phys. Rev. Lett. 102, 017205 (2009).
 S. M. Winter et al., J. Phys. Condens. Matter 29, 493002 (2017).
 J. Rusnačko, D. Gotfryd, and J. Chaloupka, Phys. Rev. B 99, 064425 (2019).