Quantum tracking control of the orientation of symmetric top molecules

TL;DR

This paper develops a method for controlling the orientation of symmetric top molecules in three dimensions using quantum tracking control, which involves directly designing shaped fields to follow desired orientation trajectories.

Contribution

It generalizes previous quantum tracking control methods to 3D symmetric top molecules and derives equations for control fields capable of tracking orientation paths.

Findings

Framework can be applied to symmetric top and linear molecules

Derived equations enable direct tracking of 3D dipole orientation

Numerical examples demonstrate effective control of molecular orientation

Abstract

The goal of quantum tracking control is to identify shaped fields to steer observable expectation values along designated time-dependent tracks. The fields are determined via an iteration-free procedure, which is based on inverting the underlying dynamical equations governing the controlled observables. In this article, we generalize the ideas in Phys. Rev. A 98, 043429 (2018) to the task of orienting symmetric top molecules in 3D. To this end, we derive equations for the control fields capable of directly tracking the expected value of the 3D dipole orientation vector along a desired path in time. We show this framework can be utilized for tracking the orientation of linear molecules as well, and present numerical illustrations of these principles for symmetric top tracking control problems.