# Quantum Control with Quantum Light of Molecular Nonadiabaticity

## TL;DR

This paper explores how using quantum light instead of classical laser fields can enhance control over molecular nonadiabatic processes, demonstrating fundamental principles and deviations in lithium fluoride.

## Contribution

It introduces a quantum light-based approach to molecular control, highlighting the importance of quantum descriptions and back-action effects in few-photon regimes.

## Key findings

- Quantum light enables new control mechanisms in molecules.
- Deviations from classical control are observed with quantum light.
- Back-action of light field becomes significant in few-photon regimes.

## Abstract

Coherent control experiments in molecules are often done with shaped laser fields. The electric field is described classically and control over the time evolution of the system is achieved by shaping the laser pulses in the time or frequency domain. Moving on from a classical to a quantum description of the light field allows to engineer the quantum state of light to steer chemical processes. The quantum field description of the photon mode allows to manipulate the light-matter interaction directly in phase-space. In this paper we will demonstrate the basic principle of coherent control with quantum light on the avoided crossing in lithium fluoride. Using a quantum description of light together with the nonadiabatic couplings and vibronic degrees of freedoms opens up new perspective on quantum control. We show the deviations from control with purely classical light field and how back-action of the light field becomes important in a few photon regime.