Photon-added entangled Barut–Girardello coherent states: non-classicality and generation A. Dehghani, B. Mojaveri, R. Jafarzadeh Bahrbeig and M. Vaez Eur. Phys. J. Plus, 135 2 (2020) 258 Published online: 18 February 2020 DOI: 10.1140/epjp/s13360-020-00175-4