Twisted-bilayer FeSe and the Fe-based superlattices
Paul M. Eugenio, Oskar Vafek
SciPost Phys. 15, 081 (2023) · published 6 September 2023
- doi: 10.21468/SciPostPhys.15.3.081
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Abstract
We derive BM-like continuum models for the bands of superlattice heterostructures formed out of Fe-chalcogenide monolayers: (I) a single monolayer experiencing an external periodic potential, and (II) twisted bilayers with long-range moire tunneling. A symmetry derivation for the inter-layer moire tunnelling is provided for both the $\Gamma$ and $M$ high-symmetry points. In this paper, we focus on moire bands formed from hole-band maxima centered on $\Gamma$, and show the possibility of moire bands with $C=0$ or ±1 topological quantum numbers without breaking time-reversal symmetry. In the $C=0$ region for $\theta→0$ (and similarly in the limit of large superlattice period for I), the system becomes a square lattice of 2D harmonic oscillators. We fit our model to FeSe and argue that it is a viable platform for the simulation of the square Hubbard model with tunable interaction strength.
Cited by 5
Authors / Affiliations: mappings to Contributors and Organizations
See all Organizations.- 1 2 Paul Myles Eugenio,
- 1 2 Oskar Vafek