Recently demonstrated solid-state single-electron sources generate different
quantum states depending on their operation condition. For adiabatic and
nonadiabatic sources, we determine the Glauber correlation function in terms
of the Floquet scattering matrix of the source. The correlation function
provides full information on the shape of the state and on its time-dependent
amplitude and phase. The coherence properties of single-electron states are
therefore essential for the production of quantum multiparticle states.