Dynamics of molecular superrotors in external magnetic field

TL;DR

This study investigates how diatomic oxygen and nitrogen molecules in high rotational states behave in external magnetic fields, revealing different interaction mechanisms and demonstrating control over their rotation planes.

Contribution

It provides the first direct visualization of molecular superrotor dynamics in magnetic fields, highlighting distinct behaviors in paramagnetic and non-magnetic molecules.

Findings

Nitrogen molecules precess around the magnetic field vector.

Oxygen molecules exhibit splitting of the rotation plane into three components.

Magnetic interaction enables control over molecular rotation planes.

Abstract

We excite diatomic oxygen and nitrogen to high rotational states with an optical centrifuge and study their dynamics in external magnetic field. Ion imaging is employed to directly visualize, and follow in time, the rotation plane of molecular superrotors. The two different mechanisms of interaction between the magnetic field and the molecular angular momentum in paramagnetic oxygen and non-magnetic nitrogen lead to the qualitatively different behaviour. In nitrogen, we observe the precession of the molecular angular momentum around the field vector. In oxygen, strong spin-rotation coupling results in faster and richer dynamics, encompassing the splitting of the rotation plane in three separate components. As the centrifuged molecules evolve with no significant dispersion of the molecular wave function, the observed magnetic interaction presents an efficient mechanism for controlling the plane of molecular rotation.