Mixed-field orientation of a thermal ensemble of linear polar molecules

TL;DR

This paper theoretically investigates how combined electrostatic and laser fields influence the rotational behavior of thermal linear molecules, demonstrating significant orientation at low temperatures or with stronger static fields.

Contribution

It provides a detailed theoretical analysis of mixed-field orientation of thermal ensembles of linear molecules, using the rigid rotor model and applying it to OCS molecules under realistic experimental conditions.

Findings

Significant molecular orientation achieved below 0.7K rotational temperature.

Orientation enhanced by stronger static electric fields.

Theoretical framework applicable to current experimental setups.

Abstract

We present a theoretical study of the impact of an electrostatic field combined with nonresonant linearly polarized laser pulses on the rotational dynamics of a thermal ensemble of linear molecules. We solve the time-dependent Schr\"odinger equation within the rigid rotor approximation for several rotational states. Using the carbonyl sulfide (OCS) molecule as a prototype, the mixed-field orientation of a thermal sample is analyzed in detail for experimentally accessible static field strengths and laser pulses. We demonstrate that for the characteristic field configuration used in current mixed-field orientation experiments, a significant orientation is obtained for rotational temperatures below 0.7K or using stronger dc fields.