Spatiotemporal Thermalization and Adiabatic Cooling of Guided Light Waves

Year: 2026

Authors: Zanaglia L., Garnier J., Carusotto I., Doya V., Michel C., Picozzi A.

Autors Affiliation: Univ Cote dAzur, Inst Phys Nice, CNRS, Nice, France; Ecole Polytech, Inst Polytech Paris, CNRS, CMAP, F-91120 Palaiseau, France; Univ Trento, Pitaevskii BEC Ctr, CNR INO, I-38123 Trento, Italy; Univ Trento, Dipartimento Fis, I-38123 Trento, Italy; Inst Univ France IUF, 1 Rue Descartes, F-75005 Paris, France; Univ Bourgogne Europe, CNRS, Lab Interdisciplinaire Carnot Bourgogne ICB UMR 63, ICB UMR 6303, F-21000 Dijon, France.

Abstract: We propose and theoretically characterize three-dimensional spatiotemporal thermalization of a continuous-wave classical light beam propagating along a multimode optical waveguide. By combining a nonequilibrium kinetic approach based on the wave turbulence theory and numerical simulations of the field equations, we anticipate that thermalizing scattering events are dramatically accelerated by the combination of strong transverse confinement with the continuous nature of the temporal degrees of freedom. In connection with the blackbody catastrophe, the thermalization of the classical field in the continuous temporal direction provides a novel intrinsic mechanism for adiabatic cooling and spatial beam condensation. This process of adiabatic cooling is distinct from other mechanisms of thermalization and provides new insights into the dynamics of far-from-equilibrium closed systems and their route to thermalization.

Journal/Review: PHYSICAL REVIEW LETTERS

Volume: 136 (5)      Pages from: 53802-1  to: 53802-8

More Information: Funding was provided by Agence Nationale de la Recherche (Grants No. ANR-23-CE30-0021, No. ANR-21-ESRE-0040) . Calculations were performed using HPC resources from Universite Cpte d’Azur’s Center Azzura and DNUM-CCUB (Universite de Bourgogne Europe) . I. C. acknowledges financial support from the PE0000023-NQSTI project by the Italian Ministry of University and Research, cofunded by the European Union-NextGeneration EU, and from Provincia Autonoma di Trento (PAT) , partly via the Q@TN initiative. I. C.’s research was supported in part by the InternationalCentre for Theoretical Sciences (ICTS) for participating in the program: Turbulence and vortex dynamics in 2D quantum fluids (code: ICTS/QUFLU2024/2) . The authors acknowledge S. Wabnitz, M. Ferraro, T. Torres, P. E. Larre, B. Kibler, and P. Bejot for valuable discussions.
KeyWords: Universal Dynamics; Turbulence
DOI: 10.1103/mqzh-w2gh