Multichannel quantum defect calculation of the phase lag in the coherent control of HI

A two-step unified multichannel quantum defect theory (MQDT) was applied to compute the competing ionization and dissociation channel phases of hydrogen iodide (HI). The phase lag between the ionization and dissociation channels in the vicinity of resonance was calculated and compared with the experimental results. The channel phase was consistent with the existing theory of the phase lag phenomenon and observed values. The incorporation of traveling wave boundary conditions gave a symmetric resonance profile which explained the previous MQDT prediction that channel phase vanished identically.