Network model for higher-order topological phases
Abstract
We introduce a two-dimensional network model that realizes a higher-order topological phase (HOTP). We find that in the HOTP the bulk and boundaries of the system are gapped, and a total of 16 corner states are protected by the combination of a four-fold rotation, a phase-rotation, and a particle-hole symmetry. In addition, the model exhibits a strong topological phase at a point of maximal coupling. This behavior is in opposition to conventional network models, which are gapless at this point. By introducing the appropriate topological invariants, we show how a point group symmetry can protect a topological phase in a network. Our work provides the basis for the realization of HOTP in alternative experimental platforms implementing the network model.
Cite
@article{arxiv.2009.07877,
title = {Network model for higher-order topological phases},
author = {Hui Liu and Selma Franca and Ali G. Moghaddam and Fabian Hassler and Ion Cosma Fulga},
journal= {arXiv preprint arXiv:2009.07877},
year = {2021}
}
Comments
13 pages, 9 figures, published version