2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/163967Exciton instability in graphene bilayer systems is studied in the case of a short-ranged Coulomb interaction and a finite voltage difference between the layers. Self-consistent exciton gap equations are derived and solved numerically and analytically under controlled approximation. We obtain that a critical strength of the Coulomb interaction exists for the formation of excitons. The critical strength depends on the amount of voltage difference between the layers and on the inter-layer hopping parameter.10 pages, 11 figuresStrongly Correlated ElectronsMaterials Sciencetext