Tunable enhancement of harmonic radiation in coupled quantum wells Yi Zhang, Yue Kuang, Chaojin Zhang, Bin Chen, Henglei Du and Chengpu Liu Eur. Phys. J. D, 76 7 (2022) 114 Published online: 05 July 2022 DOI: 10.1140/epjd/s10053-022-00443-1