MQDT operatorial formalism analysis of molecular Rydberg states in weak electric fields : application to Na2

P. Brevet , Ch. Bordas , M. Broyer , G. Jalbert , P. Labastie

We present the Multichannel Quantum Defect Theory in its operatorial form and its application to the problem of Rydberg states of a diatomic molecule in external electric fields. The theoretical analysis consists in the description of the close connection between the resolvent operator and the Density-Of-State matrix which defines the whole spectrum. In the particular case of the discrete spectrum in weak electric fields, bound states are deduced from the poles of this matrix. We give an example of the use of this theory in the case of Na2 but it could be applied to any other non hydrogenic system as well. Calculated spectra of Rydberg states of Na2 in weak fields are compared to experimental data. The presence of extra-lines and the emergence of hydrogenic multiplets is emphasized. We also show the influence of the penetrating nfΛ series on the shape of the multiplets and estimate orders of magnitude for their quantum defects.

Domaines: Articles anciens

P. Brevet, Ch. Bordas, M. Broyer, G. Jalbert, P. Labastie. MQDT operatorial formalism analysis of molecular Rydberg states in weak electric fields : application to Na2. Journal de Physique II, 1991, 1 (8), pp.875-897. ⟨10.1051/jp2:1991114⟩. ⟨jpa-00247561⟩