Signatures of symmetry-induced quantum-interference effects observed in above-threshold-ionization spectra of molecules

We report on an experimental observation of the qualitative signatures of symmetry-induced quantum-interference effects in above-threshold-ionization spectra of ${\mathrm{O}}_{2}$ (antibonding ${\ensuremath{\pi}}_{g}$ symmetry) and ${\mathrm{N}}_{2}$ (bonding ${\ensuremath{\sigma}}_{g}$ symmetry). It confirms the corresponding predictions of intense-field S-matrix theory.