“…A notable exception is Ref. [11] where the production of triple-NOON states of the form e iϕ1 |N, 0, 0 + e iϕ2 |0, N, 0 + e iϕ3 |0, 0, N was theoretically investigated for a gas of ultracold bosonic atoms. A key ingredient in those bosonic quantum gases is the presence of atom-atom interaction, which induces a spectral separation of NOON states from other states with identical total population of the modes.…”