Non-Markovian collisional dynamics probed with laser-aligned molecules

The Markov, as well the secular, approximations are key assumptions that have been widely used to model decoherence in a large variety of open quantum systems, but, far intermolecular collisions considered, very little has done time domain. In order probe limits both approximations, we here study influence pressure on alignment revivals (echoes) created properly chosen gas mixtures (HCl and ${\mathrm{CO}}_{2}$, pure diluted He) by one (two) intense short laser pulse(s). Experiments direct predictions using molecular-dynamics simulations consistently demonstrate, through analyses at times $(<15 \mathrm{ps})$ after kick(s), breakdown these some selected systems. We show nonadiabatic laser-induced molecular technique this paper directly provide detailed information physical mechanisms involved collisional dissipation. Besides ``fundamental'' interest, our findings also potential practical applications for radiative heat transfer planetary atmospheres climate studies. Indeed, delays dipole autocorrelation function monitoring light absorption spectrum correspond detunings from optical resonances frequency domain, thus influencing atmospheric transparency windows. Furthermore, fact approach tested linear rotors can potentially be applied almost any mixture (including, instance, nonlinear and/or reacting molecules) further strengthens broadens perspectives it opens.