Probing multiphoton light-induced molecular potentials

TL;DR

This paper explores how intense laser fields modify molecular potential energy surfaces, revealing complex light-induced effects and enabling control over molecular dissociation through experimental and theoretical analysis of H₂⁺.

Contribution

It demonstrates the first direct observation of modulated angular proton distributions caused by ultrafast dynamics on light-induced molecular potentials in H₂⁺.

Findings

Observation of modulated proton angular distributions

Control of molecular dissociation via laser parameters

Uncovering complex light-induced potential energy surfaces

Abstract

The strong coupling between intense laser fields and valence electrons in molecules causes a distortion of the potential energy hypersurfaces which determine the motion of nuclei in a molecule and influences possible reaction pathways. The coupling strength varies with the angle between the light electric field and valence orbital, and thereby adds another dimension to the effective molecular potential energy surface, allowing for the emergence of light-induced conical intersections. Here, we demonstrate in theory and experiment that the full complexity of such light-induced potential energy surfaces can be uncovered. In H$_2^+$, the simplest of molecules, we observe a strongly modulated angular distribution of protons which has escaped prior observation. These modulations directly result from ultrafast dynamics on the light-induced molecular potentials and can be modified by varying the amplitude, duration and phase of the mid-infrared dressing field. This opens new opportunities for manipulating the dissociation of small molecules using strong laser fields.