Fig. 3: Spectral function of diatomic molecules.

Spectral function of A NaH, B KH. The circuits to obtain the spectral function are shallow three-qubit circuits that do not require the iToffoli gates. A broadening factor of η = 0.75 eV is used to generate both the exact and the experimental spectra. The experimental spectral functions are in quantitative agreement with the exact ones, with a maximum peak height deviation of 10.6%.