Extreme Ultraviolet Wave Packet Interferometry of the Autoionizing HeNe Dimer

Femtosecond extreme ultraviolet wave packet interferometry (XUV-WPI) was applied to study resonant interatomic Coulombic decay (ICD) in the HeNe dimer. The high demands on phase stability and sensitivity for vibronic XUV-WPI of molecular-beam targets are met using an XUV phase-cycling scheme. The detected quantum interferences exhibit vibronic dephasing and rephasing signatures along with an ultrafast decoherence assigned to the ICD process. A Fourier analysis reveals the molecular absorption spectrum with high resolution. The demonstrated experiment shows a promising route for the real-time analysis of ultrafast ICD processes with both high temporal and high spectral resolution.

Automated summary

Femtosecond extreme ultraviolet wave packet interferometry (XUV-WPI) was used to study resonant interatomic Coulombic decay (ICD) in the HeNe dimer. By utilizing an XUV phase-cycling scheme, the high demands on phase stability and sensitivity for vibronic XUV-WPI of molecular-beam targets were met. The experiment demonstrated vibronic dephasing and rephasing signatures, ultrafast decoherence related to the ICD process, and high-resolution molecular absorption spectrum. This study provides a promising method for real-time analysis of ultrafast ICD processes with high temporal and spectral resolution.