Spontaneous symmetry breakings in two-dimensional kagome lattice

Abstract

We study spontaneous symmetry breakings for fermions (spinless and spinful) on a two-dimensional kagome lattice with nearest-neighbor repulsive interactions in weak coupling limit, and focus in particular on topological Mott insulator instability. It is found that at $\frac{1}{3}$-filling where there is a quadratic band crossing at $\Gamma$-point, in agreement with Ref. 1, the instabilities are infinitesimal and topological phases are dynamically generated. At $\frac{2}{3}$-filling where there are two inequivalent Dirac points, the instabilities are finite, and no topological phase is favored at this filling without breaking the lattice translational symmetry. A ferromagnetic quantum anomalous Hall state with infinitesimal instability is further proposed at half-filling of the bottom flat band.

5 pages, 3 figures, Published in Phys. Rev. B

References in corpus (11)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Spin Dynamics of the Spin-1/2 Kagome Lattice Antiferromagnet ZnCu_3(OH)_6Cl_2
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• Topological Mott Insulators
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• Fermi liquid instabilities in the spin channel
• ^{63}Cu, ^{35}Cl, and ^{1}H NMR in the S=1/2 Kagomé Lattice ZnCu_{3}(OH)_{6}Cl_{2}
• Dynamic generation of spin orbit coupling
• Time-Reversal Symmetry Breaking and Spontaneous Anomalous Hall Effect in Fermi Fluids
• Modified kagome physics in the natural spin-1/2 kagome lattice systems - kapellasite Cu3Zn(OH)6Cl2 and haydeeite Cu3Mg(OH)6Cl2
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Cited by in corpus (16)

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• Interaction-driven topological insulators on the kagome and the decorated honeycomb lattices
• Correlation effects in two-dimensional topological insulators
• Quantum states and intertwining phases in kagome materials
• Charge instabilities and topological phases in the extended Hubbard model on the honeycomb lattice with enlarged unit cell
• Novel magnetic orderings in the kagome Kondo-lattice model
• Topological phases in layered pyrochlore oxide thin films along the [111] direction
• Theory of nematic charge orders in kagome metals
• Spontaneous quantum Hall effect via thermally induced quadratic Fermi point
• Change of an insulator's topological properties by a Hubbard interaction
• Complex magnetic and spatial symmetry breaking from correlations in kagome flat bands
• Infrared phonons as a probe of a spin-liquid states in herbertsmithite ZnCu3(OH)6Cl2
• Three-dimensional higher-order saddle points induced flat bands in Co-based kagome metals
• Tuning electronic pairing by uniaxial strain in kagome lattices
• Topological Aspects of Dirac Fermions in a Kagomé Lattice