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| Phase transition (physics) | |
|---|---|
| Name | Phase transition (physics) |
| Type | Physical phenomenon |
| Field | Physics |
Phase transition (physics) Phase transitions are transformations between distinct states of matter or phases driven by changes in external parameters such as temperature, pressure, or magnetic field. These transformations are central to thermodynamics, statistical mechanics, condensed matter physics and materials science and connect to landmark concepts associated with Ludwig Boltzmann, James Clerk Maxwell, Josiah Willard Gibbs, Lev Landau, and Pieter Zeeman.
Phase transitions describe qualitative changes in macroscopic properties when control parameters cross critical thresholds, exemplified by the liquid–gas transition near the André-Marie Ampère-named critical point and the ferromagnetic transition near the Pierre Curie point. They underpin paradigms in Enrico Fermi-related nuclear matter, Lev Landau-theory-based superconductivity as in Heike Kamerlingh Onnes's experiments, and cosmological phase changes discussed by Alan Guth and Andrei Linde in inflationary scenarios. Studies of transitions draw on concepts developed by Johann Heinrich Lambert-era thermodynamics, Kamerlingh Onnes-style cryogenics, and modern techniques from groups at Bell Labs, CERN, and national laboratories such as Los Alamos National Laboratory.
Classification of transitions uses Ehrenfest and Landau frameworks, distinguishing first-order transitions with latent heat (e.g., ice–water studied by Joseph Fourier and James Prescott Joule) from continuous transitions marked by divergent susceptibilities as in Pierre Curie's ferromagnets. Order parameters introduced by Lev Landau (scalar, vector, tensor) characterize broken symmetries in systems studied by Wolfgang Pauli, Paul Dirac, and Richard Feynman; examples include the magnetization in Ernest Rutherford-era magnets, the superfluid density in Pyotr Kapitsa's helium experiments, and the superconducting gap in John Bardeen and Leon Cooper's theory. Topological order parameters emerge in works by David Thouless, F. Duncan M. Haldane, and J. Michael Kosterlitz to classify transitions without symmetry breaking, relating to quantum Hall effects researched by Klaus von Klitzing and Horst Störmer.
Thermodynamic descriptions employ free energies developed by Josiah Willard Gibbs and stability criteria used by Max Planck to identify coexistence curves and spinodals; statistical mechanics derives macroscopic behavior from microscopic ensembles pioneered by Ludwig Boltzmann, James Clerk Maxwell, and refined via Kadanoff-style renormalization. Lattice models such as the Ising model studied by Ernst Ising and Wilhelm Lenz, the Potts model, and the XY model capture critical behavior analyzed by Leo Kadanoff, Kenneth Wilson, and Michael Fisher. Methods from John von Neumann-related computational physics and Monte Carlo algorithms developed in conjunction with work at Los Alamos National Laboratory enable numerical studies of partition functions, correlation functions, and finite-size scaling.
Critical phenomena feature scale invariance and universality classes elucidated by Kenneth Wilson's renormalization group and conformal field theory approaches advanced by Alexander Zamolodchikov and John Cardy. Critical exponents measured in experiments by teams at CERN, Bell Labs, and Brookhaven National Laboratory match predictions from field theories such as the phi-four model and conformal bootstrap programs influenced by Alexander Polyakov and Miguel Virasoro. Concepts like scaling functions, hyperscaling relations, and anomalous dimensions connect to work by Michael Fisher, Benjamin Widom, and Leo Kadanoff and are applied from classical fluids studied by Andrews to magnetic systems probed by Ernest Rutherford-era magnetometry.
Dynamics of transitions invoke time-dependent Ginzburg–Landau equations associated with Lev Landau and Vitaly Ginzburg, kinetic theories from Richard Feynman-adjacent many-body physics, and non-equilibrium frameworks such as driven-dissipative systems studied at Max Planck Institute and MIT. Phenomena include spinodal decomposition, coarsening dynamics analyzed by Alan Bray, and absorbing-state transitions linked to directed percolation studied by G. I. Taylor and H. K. Janssen. Nonequilibrium phase transitions feature pattern formation in Rayleigh–Bénard convection experiments by Lord Rayleigh and turbulence transitions investigated by Lars Onsager and Andrey Kolmogorov.
Classic examples include melting and freezing in materials researched by William Thomson, 1st Baron Kelvin and F. A. Cotton, vaporization and condensation in cryogenics by Heike Kamerlingh Onnes, magnetic ordering in materials central to James Dewar's experiments, superconducting transitions in work by John Bardeen, Leon Cooper, and Robert Schrieffer, and superfluid transitions in helium explored by Pyotr Kapitsa and John F. Allen. Modern applications span phase-change memory devices from IBM research, quantum phase transitions in ultracold gases studied at Joint Institute for Laboratory Astrophysics and Max Planck Institute for Quantum Optics, and topological transitions underlying devices inspired by Klaus von Klitzing's quantum Hall experiments and Charles Kittel's solid-state research.
Experimental probes include calorimetry techniques refined by James Prescott Joule and Pierre Curie, neutron scattering at facilities such as Oak Ridge National Laboratory and Institut Laue–Langevin, X-ray scattering at SLAC National Accelerator Laboratory and European Synchrotron Radiation Facility, magnetic resonance methods from Isidor Rabi and Felix Bloch, and transport measurements developed at Bell Labs and IBM. Advanced microscopy and spectroscopic tools at institutions like Lawrence Berkeley National Laboratory and Max Planck Institute permit imaging of domain dynamics, while ultrafast pump–probe spectroscopy pioneered at Stanford University resolves nonequilibrium dynamics on femtosecond timescales.