Quantum battles in attoscience: tunnelling Cornelia Hofmann, Alexander Bray, Werner Koch, Hongcheng Ni and Nikolay I. Shvetsov-Shilovski Eur. Phys. J. D, 75 7 (2021) 208 Published online: 20 July 2021 DOI: 10.1140/epjd/s10053-021-00224-2