# Ill-Defined Topological Phases in Local Dispersive Photonic Crystals.

@article{Prudncio2021IllDefinedTP, title={Ill-Defined Topological Phases in Local Dispersive Photonic Crystals.}, author={Filipa R. Prud{\^e}ncio and M{\'a}rio G. Silveirinha}, journal={Physical review letters}, year={2021}, volume={129 13}, pages={ 133903 } }

In recent years there has been a great interest in topological materials and in their fascinating properties. Topological band theory was initially developed for condensed matter systems, but it can be readily applied to arbitrary wave platforms with few modifications. Thus, the topological classification of optical systems is usually regarded as being mathematically equivalent to that of condensed matter systems. Surprisingly, here we find that both the particle-hole symmetry and the…

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