2021/11/30 by Jan Meibohm, Massimiliano Esposito · 1 citation
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Critical exponent #Critical phenomena #Cusp (singularity) #Dynamical systems theory #Magnetization #Non-equilibrium thermodynamics #Phase transition #Relaxation (psychology) #Saddle #Singularity #Statistical Mechanics and Entropy #Theoretical and Computational Physics #cond-mat.stat-mech
paper · pdf · doi:10.1103/physrevlett.128.110603
published as Phys. Rev. Lett. 128, 110603 (2022) · 5+10 pages, 3+2 figures
openalex created_date 2021/11/22 · arxiv created 2022/03/11 · openalex publication_date 2022/03/18 · arxiv updated 2022/03/23 · openalex updated_date 2026/08/05
We uncover a finite-time dynamical phase transition in the thermal relaxation of a mean-field magnetic model. The phase transition manifests itself as a cusp singularity in the probability distribution of the magnetisation that forms at a critical time. The transition is due to a sudden switch in the dynamics, characterised by a dynamical order parameter. We derive a dynamical Landau theory for the transition that applies to a range of systems with scalar, parity-invariant order parameters. Close to criticalilty, our theory reveals an exact mapping between the dynamical and equilibrium phase transitions of the magnetic model, and implies critical exponents of mean-field type. We argue that interactions between nearby saddle points, neglected at the mean-field level, may lead to critical, spatiotemporal fluctuations of the order parameter, and thus give rise to novel, dynamical critical phenomena.