Stability of Discrete Breathers in Magnetic Metamaterials

We consider the discrete Klein–Gordon equation for magnetic metamaterials derived by Lazarides, Eleftheriou, and Tsironis Phys Rev Lett 97:157406, 2006). We obtain a general criterion for spectral stability of multi-site breathers for a small coupling constant. We show how this criterion differs from the one derived in the standard discrete Klein–Gordon equation (Koukouloyannis and Kevrekidis, Nonlinearity 22:2269–2285, 2009; Pelinovsky and Sakovich, Nonlinearity 25:3423–3451, 2012).