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arXiv · 2303.01452

Stackings and effective models of bilayer dice lattices

P. O. Sukhachov·D. O. Oriekhov·E. V. Gorbar
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Abstract

We introduce and classify nonequivalent commensurate stackings for bilayer dice or $\mathcal{T}_3$ lattice. For each of the four stackings with vertical alignment of sites in two layers, a tight-binding model and an effective model describing the properties in the vicinity of the threefold band-crossing points are derived. Focusing on these band-crossing points, we found that although the energy spectrum remains always gapless, depending on the stacking, different types of quasiparticle spectra arise. They include those with flat, tilted, anisotropic semi-Dirac, and $C_3$-corrugated energy bands. We use the derived tight-binding models to calculate the density of states and the spectral function. The corresponding results reveal drastic redistribution of the spectral weight due to the inter-layer coupling that is unique for each of the stackings.

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P. O. Sukhachov, D. O. Oriekhov, E. V. Gorbar. 2023-03-02. Stackings and effective models of bilayer dice lattices. https://doi.org/10.1103/physrevb.108.075166

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