Giant Kerr–quintic–septic nonlinearities in semiconductor quantum wells Monika Nath, Rohit Mukherjee and Nitu Borgohain Eur. Phys. J. Plus, 137 8 (2022) 903 Published online: 08 August 2022 DOI: 10.1140/epjp/s13360-022-03106-7