Nature of equidistant negative differential resonances in tunneling spectra of ultrasmall nanoparticles

A model of tunneling multiresonant electronic transitions in nanocontacts containing ultrasmall nanoparticles with adsorbed atoms has been developed. Mechanisms of the formation of series of equidistant negative differential resistances in tunneling spectra of these structures have been analyzed. The possibility of the coexistence of equidistant series of two types, Coulomb and vibrational, has been shown. The signatures for identification of these series have been formulated. Tunneling spectra of ultrasmall metal nanoparticles containing information on their electron vibrational subsystems have been interpreted.