Interaction-driven Chern insulating phases in the α−T3 lattice with Rashba spin-orbit coupling
The magnetic interaction is a necessary ingredient to break the time-reversal symmetry in realizing quantum anomalous Hall, or Chern insulating phases. Here, we study topological phases in the α−T3 model, a minimal theoretical model supporting the flat band, taking account of Rashba spin-orbit coupl...
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Veröffentlicht in: | iScience 2023-09, Vol.26 (9), p.107546, Article 107546 |
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Sprache: | eng |
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Zusammenfassung: | The magnetic interaction is a necessary ingredient to break the time-reversal symmetry in realizing quantum anomalous Hall, or Chern insulating phases. Here, we study topological phases in the α−T3 model, a minimal theoretical model supporting the flat band, taking account of Rashba spin-orbit coupling and flat-band-induced spontaneous ferromagnetism. By analyzing the interaction-driven phase diagrams, band structures, topological edge states, and topological invariants, we demonstrate that this system offers a platform for realizing a wide range of phases, including normal insulators, semimetals, and Chern insulators. Uniquely, there exist both high-Chern-number insulators and valley-polarized Chern insulators. In the latter phase, edge channels exist in the single valley, leading to nearly 100% valley polarization. These findings demonstrate the potential of interaction-driven systems in realizing exotic phases and their promising role in future applications in topology electronics and valleytronics.
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•Topological phase diagram in the α−T3 model with Rashba spin-orbit coupling is given•Interplay between Rashba coupling and flat-band ferromagnetism is explored•Chern insulator phases are predicted•Valley-polarized Chern insulator phases are also predicted
Condensed matter physics; Magnetism; Nanomaterials |
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ISSN: | 2589-0042 2589-0042 |
DOI: | 10.1016/j.isci.2023.107546 |