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4 février 2021: 1 événement

séminaire

  • Topological order and fractionalized fermionic quantum criticality in spin-orbital Mott insulators

    Jeudi 4 février 11:00-12:00 - Urban Seifert - Laboratoire de Physique, Ecole Normale Supérieure de Lyon

    Topological order and fractionalized fermionic quantum criticality in spin-orbital Mott insulators

    Résumé : I will report on our recent construction of generalized spin (and orbital) models, which can be solved exactly using Kitaev’s construction, giving rise to quantum-disordered phases with gapless Majorana fermions hopping in the background of a static Z2 gauge field. By opening up a topologically non-trivial gap we systematically obtain microscopic lattice models for Kitaev’s sixteenfold way of anyon theories.
    Further, these models permit realistic gauge-invariant four-fermion interactions, which drive quantum phase transitions between distinct gapless fractionalized phases. We study these transitions by making use of large-scale numerical results, as well as epsilon expansion and large-N methods. The respective fermionic quantum critical points lie in fractionalized Gross-Neveu universality classes in (2+1)-dimensions, with the spectra at the quantum critical point reflecting the nontrivial topology of the adjacent phases. Our results are potentially relevant for Mott insulators with d1 electronic configurations and strong spin-orbit coupling, or for twisted bilayer structures of Kitaev materials.

    Lieu : ONLINE

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