Eur. Phys. J. B 67, 329-336 (2009)
https://doi.org/10.1140/epjb/e2008-00437-9

Divide and conquer: resonance induced by competitive interactions

¹ Departamento de Física and CFP, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre 687, 4169–, 007 Porto, Portugal
² IFISC (Instituto de Física Interdisciplinar y Sistemas Complejos), CSIC-UIB, Ed. Mateu Orfila, Campus UIB, 07122 Palma de Mallorca, Spain

Corresponding author: ^a tvmartins@fc.up.pt

Received: 29 May 2008
Revised: 23 October 2008
Published online: 4 December 2008

Abstract

We study an Ising model in a network with disorder induced by the presence of both attractive and repulsive links and subjected to a periodic subthreshold signal. By means of numerical simulations and analytical calculations we give evidence that the global response of the system reaches a maximum value for a given fraction of the number of repulsive interactions. The model can represent a network of spin-like neurons with excitatory and inhibitory couplings, or a simple opinion spreading model. In this context, attractive/repulsive links represent friends and enemies. “Divide and Conquer” refers to the fact that in order to force a society to adopt a new point of view, it helps to break its homogeneity by fostering enmities amongst its members.