Year: 2026
Type: preprint
Abstract: The critical behavior of a system near a continuous phase transition is commonly characterized by power laws and a set of universal critical exponents. Yet universality at phase transitions has even more fundamental manifestations. It dictates that all observables follow universal scaling functions, which may extend beyond simple power laws. Furthermore, microscopic details are captured entirely by only two system-specific scale factors, that rescale any measured quantity onto its universal form. In this work, we report the experimental validation of this prediction in ultracold lattice Bose gases undergoing the superfluid transition. We extract the scale factors by collapsing the order-parameter cumulants measured at varying entropies. We show that these factors specify scaling functions governing both the order-parameter distribution and two-point correlations. By measuring these scaling functions, we also determine three critical exponents $β$, $γ$ and $ν$. Our results provide an experimental demonstration that universal scaling is simultaneously obeyed by multiple observables in a quantum many-body system.
Source: arXiv (Cornell University)
Institutions: Centre National de la Recherche Scientifique, Université Paris-Saclay, Institut d’Optique Graduate School, Laboratoire Charles Fabry, Laboratoire de Physique de l'ENS de Lyon, Sorbonne Université, Laboratoire de Physique Théorique de la Matière Condensée, Institut Universitaire de France, Université de Lille, Laboratoire de Physique des Lasers, Atomes et Molécules
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funder: Agence Nationale de la Recherche
OpenAlex ID: W7208734514