Model of n-type quadruple δ-doped GaAs quantum wells Humberto Noverola-Gamas, Luis M. Gaggero-Sager and Outmane Oubram Eur. Phys. J. B, 93 1 (2020) 18 Published online: 28 January 2020 DOI: 10.1140/epjb/e2019-100412-7