Probing molecular photophysics in a matter-wave interferometer

TL;DR

This paper demonstrates that matter-wave interferometry with a laser can precisely measure various molecular photophysical parameters, providing a novel approach to molecular characterization.

Contribution

It introduces a method using matter-wave diffraction to accurately determine molecular photophysical properties, including polarizabilities, absorption cross sections, and relaxation rates.

Findings

Accurate measurement of molecular parameters via matter-wave diffraction.

Analysis accounts for laser coherence, gravitational effects, and beam imperfections.

The method achieves high precision with finite particle numbers.

Abstract

We show that matter-wave diffraction off a single standing laser wave can be used as an accurate measurement scheme for photophysical molecular parameters. These include state-dependent optical polarizabilities and photon-absorption cross sections, the relaxation rates for fluorescence, internal conversion, and intersystem crossing, as well as ionization or cleavage probabilities. We discuss how the different photophysical processes manifest as features of the interference pattern, and we determine the accuracy of molecular parameters estimated from a realistic measurement with finite particle numbers. The analysis is based on an analytic calculation in Wigner representation, which accounts for the laser-induced coherent and incoherent dynamics, for the finite longitudinal and transverse coherence in the matter-wave beam, the gravitational and Coriolis acceleration, and an imperfect standing laser wave.