2014/09/11 by Igor N. Karnaukhov, Igor O. Slieptsov · 6 citations
Mathematics · Physics and Astronomy · #Advanced Condensed Matter Physics #Combinatorics #Condensed matter physics #Fermion #Ground state #Ising model #Lattice (music) #Mathematics #Phase (matter) #Phase diagram #Phase transition #Physics #Quantum #Quantum many-body systems #Quantum mechanics #Quantum phase transition #Square lattice #Symmetry protected topological order #Topological Materials and Phenomena #Topological degeneracy #Topological insulator #Topological order #Topology (electrical circuits) #cond-mat.str-el
paper · pdf · doi:10.1140/epjb/e2014-50353-4
published in The European Physical Journal B 87(10) (Springer Science+Business Media) · 8 pages, 9 figures
arxiv created 2014/09/11 · openalex publication_date 2014/10/01 · arxiv updated 2014/10/17 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
In this paper we propose an exactly solvable model of a topological insulator defined on a spin-1/2 square decorated lattice. Itinerant fermions defined in the framework of the Haldane model interact via the Kitaev interaction with spin-1/2 Kitaev sublattice. The presented model, whose ground state is a non-trivial topological phase, is solved exactly. We have found out that various phase transitions without gap closing at the topological phase transition point outline the separate states with different topological numbers. We provide a detailed analysis of the model's ground-state phase diagram and demonstrate how quantum phase transitions between topological states arise. We have found that the states with both the same and different topological numbers are all separated by the quantum phase transition without gap closing. The transition between topological phases is accompanied by a rearrangement of the spin subsystem's spectrum from band to flat-band states.