Comment on "Floquet Fractional Chern Insulators"

Luca D'Alessio

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arXiv · 1412.3481

Comment on "Floquet Fractional Chern Insulators"

Luca D'Alessio

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Abstract

In a recent paper [Phys. Rev. Lett. 112 156801 (2014)], Grushin et al. studied a Fermi-Hubbard-model for spinful electrons on a honeycomb lattice coupled to an external polarized electric field. By computing the Floquet Hamiltonian perturbatively to order $ω^{-1}$ (where $ω$ is the frequency of the drive) they predicted that, for specific values of the driving and filling, the system can transition into a Fractional Chern Insulator. In this comment we point out that: i) the calculation of the Floquet Hamiltonian misses some terms of order $ω^{-1}$ and ii) the assumption that the Floquet bands are filled as in time-independent systems is questionable.

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Luca D'Alessio. 2014-12-10. Comment on "Floquet Fractional Chern Insulators". https://arxiv.org/abs/1412.3481

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