Chern-Simons theory and atypical Hall conductivity in the Varma phase
Abstract
In this letter, we analyze the topological response of a fermionic model defined on the Lieb lattice in presence of an electromagnetic field. The tight-binding model is built in terms of three species of spinless fermions and supports a topological Varma phase due to the spontaneous breaking of time-reversal symmetry. In the low-energy regime, the emergent effective Hamiltonian coincides with the so-called Duffin-Kemmer-Petiau (DKP) Hamiltonian, which describes relativistic pseudospin-0 quasiparticles. By considering a minimal coupling between the DKP quasiparticles and an external Abelian gauge field, we calculate both the Landau-level spectrum and the emergent Chern-Simons theory. The corresponding Hall conductivity reveals an atypical quantum Hall effect, which can be simulated in an artificial Lieb lattice.
Keywords
Cite
@article{arxiv.1710.07916,
title = {Chern-Simons theory and atypical Hall conductivity in the Varma phase},
author = {N. Menezes and C. Morais Smith and Giandomenico Palumbo},
journal= {arXiv preprint arXiv:1710.07916},
year = {2018}
}
Comments
5 pages, 3 figures; New version with an improved discussion about our findings