Macroscopic Spin-Orbit Interaction through Strong-Field Pumping of Inhomogeneously Aligned Molecular Ensemble

TL;DR

This paper demonstrates how strong-field bi-chromatic pumping of aligned molecules induces macroscopic spin-orbit interactions, resulting in high harmonic generation with orbital angular momentum determined by pump helicity, using TDDFT simulations.

Contribution

It introduces a novel macroscopic spin-orbit interaction mechanism in inhomogeneous molecular ensembles under strong-field excitation.

Findings

High harmonic radiation carries orbital angular momentum.

Sign of OAM is controlled by pump helicity.

Validated with TDDFT simulations on H2+ and N2.

Abstract

We study the strong-field interaction of a helical bi-chromatic pump with an anisotropic and inhomogeneous molecular system in the form of planar distribution of radially aligned molecular ensemble. This setting gives rise to macroscopic spin-orbit interaction where High Harmonic radiation is emitted while imbued with Orbital Angular Momentum (OAM) whose sign is directly dictated by the helicity of the pump field. We demonstrate this phenomenon in ensembles of $H_2^+$ and $N_2$ molecules with Time-Dependent Density Functional Theory (TDDFT) simulations.