Observation of the diffusive Nambu-Goldstone mode of a non-equilibrium phase transition
Abstract
Second-order phase transitions are governed by spontaneous symmetry breaking, which yield collective excitations with a gapless spectrum called Nambu-Goldstone (NG) modes. While NG modes in conservative systems are propagating excitations, non-equilibrium phase transitions have been predicted to feature a diffusive NG mode. We present the first experimental evidence of a diffusive NG mode in a non-equilibrium Bose-Einstein condensate of microcavity polaritons. The NG mode is observed as a spectral narrowing in the spectroscopic response of the condensate. Additionally, explicitly breaking the symmetry causes the opening of a gap in the spectrum and the disappearance of the NG mode. Our observations confirm the diffusive dynamics of the NG mode of non-equilibrium phase transitions and establish a promising framework to investigate fundamental questions in statistical mechanics.
Keywords
Cite
@article{arxiv.2310.11903,
title = {Observation of the diffusive Nambu-Goldstone mode of a non-equilibrium phase transition},
author = {Ferdinand Claude and Maxime J. Jacquet and Michiel Wouters and Elisabeth Giacobino and Quentin Glorieux and Iacopo Carusotto and Alberto Bramati},
journal= {arXiv preprint arXiv:2310.11903},
year = {2023}
}
Comments
8 pages + refs + appendix, 6 figures