Fast and precise chiroptical spectroscopy by photoelectron elliptical dichroism

Area of Science:

• Physical Chemistry
• Spectroscopy
• Quantum Optics

Background:

• Chiral molecules exhibit distinct interactions with polarized light.
• Photoelectron angular distributions reveal molecular asymmetry.
• Measuring enantiomeric composition is crucial in chemistry and biology.

Purpose of the Study:

• To report high-precision measurements of photoelectron elliptical dichroism (PEELD).
• To demonstrate the structural sensitivity and spectroscopic utility of PEELD.
• To showcase the application of machine learning for analyzing PEELD data.

Main Methods:

• Utilizing elliptically polarized femtosecond laser pulses.
• Employing an optical cavity to enhance signal-to-noise ratio.
• Performing momentum-resolved PEELD measurements on 16 diverse molecules.

Main Results:

• Achieved 0.04% precision in determining enantiomeric excess using low-power lasers.
• Demonstrated PEELD's high sensitivity to molecular structure.
• Successfully applied convolutional neural networks to retrieve sample composition from PEELD maps.

Conclusions:

• PEELD is a powerful, precise technique for analyzing molecular chirality.
• The method is applicable to a wide range of molecules.
• Machine learning integration enhances the analytical capabilities of PEELD.