Fermi energy
concept in quantum mechanics referring to the energy difference between the highest and lowest occupied single-particle states in a quantum system of non-interacting fermions at absolute zero temperature
en-US/ˈfɝmi ˈɛnɚd͡ʒi/
en-GB/ˈfɜːmɪ ˈɛnəd͡ʒɪ/