Enhanced coherent optical effects in Ξ-shaped hybrid quantum-plasmonic systems Hamid R. Hamedi, Julius Ruseckas, Vassilios Yannopapas and Emmanuel Paspalakis Eur. Phys. J. Plus, 139 4 (2024) 314 Published online: 05 April 2024 DOI: 10.1140/epjp/s13360-024-05102-5