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Characterization of topological phases in the compass ladder model

Haghshenas, R ; Sharif University of Technology

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  1. Type of Document: Article
  2. DOI: 10.1088/0953-8984/28/17/176001
  3. Publisher: Institute of Physics Publishing
  4. Abstract:
  5. The phase diagram of the quantum compass ladder model is investigated through numerical density matrix renormalization group based on infinite matrix product state algorithm and analytic effective perturbation theory. For this model we obtain two symmetry-protected topological phases, protected by a Z2 × Z2 symmetry, and a topologically-trivial Z2-symmetry-breaking phase. The symmetry-protected topological phases - labeled by symmetry fractionalization - belong to different topological classes, where the complexconjugate symmetry uniquely distinguishes them. An important result of this classification is that, as revealed by the nature of the Z2-symmetry-breaking phase, the associated quantum phase transitions are accompanied by an explicit symmetry breaking, and thus a local-order parameter conclusively identifies the phase diagram of the underlying model. This is in stark contrast to previous studies which require a non-local string order parameter to distinguish the corresponding quantum phase transitions. We numerically examine our results and show that the local-order parameter is related to the magnetization exponent 0.12 ± 0.01
  6. Keywords:
  7. Infinite matrix product states ; Symmetry fractionalization ; Symmetry-protected topological phase ; Group theory ; Ladders ; Perturbation techniques ; Phase diagrams ; Phase transitions ; Quantum theory ; Statistical mechanics ; Density matrix renormalization group ; Infinite matrix products ; Perturbation theory ; Quantum phase transitions ; String order parameter ; Symmetry-breaking ; Topological phase ; Topological phasis ; Topology
  8. Source: Journal of Physics Condensed Matter ; Volume 28, Issue 17 , 2016 ; 09538984 (ISSN)
  9. URL: http://iopscience.iop.org/article/10.1088/0953-8984/28/17/176001