Path integral approach to the problem of rotational excitation of molecules by an ultrashort laser pulses sequence

TL;DR

This paper develops a path integral method to analyze the rotational excitation of nitrogen molecules by ultrashort laser pulses, revealing complex dependencies and resonances in excitation probabilities through computer simulations.

Contribution

It introduces a novel path integral approach to quantum rotational dynamics under ultrashort laser pulse sequences, providing new insights into excitation probabilities and resonance phenomena.

Findings

Resonances in excitation probabilities align with experimental results

Complex dependency of high rotation state excitation on pulse sequence periods

Path integral representation effectively models multi-level quantum systems

Abstract

The amplitude and probability of quantum transitions are represented as a path integrals in energy state space of the investigated multi-level quantum system. Using this approach we consider rotational dynamics of nitrogen molecules $^{14}N_{2}$ and $^{15}N_{2}$ which interact with a sequence of ultrashort laser pulses. Our computer simulations indicate the complex dependency of the high rotation states excitation probability upon ultrashort laser pulses sequence periods. We observe pronounced resonances, which correspond to the results of some experiments.