Free depends on the context. These electrons are in a potential well, they're in a bound state. Actual atoms are just an example of that. My point was that conceptually both situations are alike, as they are bound states you get discrete spectra (roughly speaking), if they were free particles you wouldn't. (Maybe those levels happen to be very close, but that's a different story. In principle the artificial atom name makes sense and talking about orbitals is not a bad analogy.)
mnl|6 years ago