Negative-refractive-index behavior in a periodic photonic metamaterial: unit-cell topology tailoring for broadband responseCevat Açıkel, Ecem Helvacı, Bilgehan B. Öner and Irem O. AlpJ. Eur. Opt. Society-Rapid Publ., 22 1 (2026) 20DOI: https://doi.org/10.1051/jeos/2026018
