The effect of nuclear-quadrupole coupling in the laser induced alignment of molecules

TL;DR

This paper theoretically investigates how nuclear-quadrupole interactions affect the laser-induced alignment of molecules, revealing conditions where these hyperfine couplings significantly influence rotational dynamics.

Contribution

It systematically analyzes the impact of nuclear-quadrupole coupling on molecular rotational dynamics during laser alignment, highlighting regimes where this effect is non-negligible.

Findings

Nuclear-quadrupole coupling significantly influences molecular rotational dynamics.

The impact varies with laser pulse shape and intensity.

Conditions where quadrupole effects cannot be ignored are identified.

Abstract

We present a theoretical study of the time-dependent laser alignment of molecules taking into account the hyperfine coupling due to nuclear-quadrupole interactions. The coupling of nuclear spins to the overall angular momentum of molecules significantly influences their rotational dynamics. Here, we systematically analyze the impact of the nuclear-quadrupole coupling on the rotational dynamics of the linear $\text{I}_2$ and the asymmetric-top diiodobenzene molecule induced by external laser fields. We explore different regimes of pulse shapes and laser-pulse intensities and detail under which conditions the quadrupole coupling cannot be neglected in the description of the laser alignment of molecules.