Dirac points merging and wandering in a model Chern insulator

Abstract

We present a model for a Chern insulator on the square lattice with complex first and second neighbor hoppings and a sublattice potential which displays an unexpectedly rich physics. Similarly to the celebrated Haldane model, the proposed Chern insulator has two topologically non-trivial phases with Chern numbers $\pm 1$. As a distinctive feature of the present model, phase transitions are associated to Dirac points that can move, merge and split in momentum space, at odds with Haldane's Chern insulator where Dirac points are bound to the corners of the hexagonal Brillouin zone. Additionally, the obtained phase diagram reveals a peculiar phase transition line between two distinct topological phases, in contrast to the Haldane model where such transition is reduced to a point with zero sublattice potential. The model is amenable to be simulated in optical lattices, facilitating the study of phase transitions between two distinct topological phases and the experimental analysis of Dirac points merging and wandering.

References in corpus (13)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• A tight-binding approach to uniaxial strain in graphene
• Topological Insulators and Nematic Phases from Spontaneous Symmetry Breaking in 2D Fermi Systems with a Quadratic Band Crossing
• Merging of Dirac points in a two-dimensional crystal
• Dirac-point engineering and topological phase transitions in honeycomb optical lattices
• Valleytronics in merging Dirac cones: All-electric-controlled valley filter, valve and universal reversible logic gate
• Time-Reversal-Invariant Hofstadter-Hubbard Model with Ultracold Fermions
• Time-Reversal Symmetry Breaking and Spontaneous Anomalous Hall Effect in Fermi Fluids
• Distant-Neighbor Hopping in Graphene and Haldane Models
• Winding vector: how to annihilate two Dirac points with the same charge
• Merging Dirac points and topological phase transitions in the tight-binding model on the generalized honeycomb lattice
• Moving and merging of Dirac points on a square lattice and hidden symmetry protection

Cited by in corpus (2)

• Strain tuned topology in the Haldane and the modified Haldane models
• Tuning Dirac nodes with correlated d-electrons in BaCo_{1-x}Ni_{x}S_{2}