Coherent Control of ultracold molecular collisions: The role of resonances

TL;DR

This paper explores how coherent control can manipulate ultracold molecule-molecule collisions, revealing the influence of resonances and how thermal averaging affects control effectiveness, with implications for understanding scattering mechanisms.

Contribution

It introduces a model for controlling ultracold molecular collisions via resonances and analyzes how thermal effects limit control, providing insights into scattering processes.

Findings

Complete control is possible around resonance energies.

Thermal averaging reduces control due to resonance distribution.

Measuring control extent reveals scattering mechanisms.

Abstract

We consider the coherent control of ultracold molecule-molecule scattering, impacted by a dense set of rovibrational resonances. To characterize the resonance spectrum, a rudimentary model based on multichannel quantum defect theory has been used to study the control of the scattering cross section and the reaction rate. Complete control around resonance energies is shown to be possible, but thermal averaging over a large number of resonances significantly reduces the extent of control of reaction rates due to the random distribution of optimal control parameters between resonances. We show that measuring the extent of coherent control could be used to extract meaningful information about the relative contribution of direct scattering versus collision complex formation, as well as about the statistical regime.