Phase transitions as a manifestation of spontaneous unitarity violation
arXiv:2209.04272 · doi:10.1088/1751-8121/ac9163
Abstract
Spontaneous symmetry breaking is well understood under equilibrium conditions as a consequence of the singularity of the thermodynamic limit. How a single global orientation of the order parameter dynamically emerges from an initially symmetric state during a phase transition, however, is not captured by this paradigm. Here, we present a series of symmetry arguments suggesting that singling out a global choice for the ordered state is in fact forbidden under unitary time evolution, even in the presence of an environment and infinitesimal symmetry breaking perturbrations. We thus argue that the observation of phase transitions in our everyday world presents a manifestation of the unitarity of quantum dynamics itself being spontaneously broken. We argue that this agrees with the observation that Schrödinger's time dependent equation is rendered unstable for macroscopic objects owing to the same singular thermodynamic limit that affects equilibrium configurations.
arXiv commentTo appear in a special issue celebrating the 80th birthday of Sir Michael Berry
References in corpus (19)
- Real Spectra in Non-Hermitian Hamiltonians Having PT Symmetry
- Exceptional Topology of Non-Hermitian Systems
- Pseudo-Hermiticity versus PT Symmetry: The necessary condition for the reality of the spectrum of a non-Hermitian Hamiltonian
- Non-Hermitian Chern bands
- Anatomy of skin modes and topology in non-Hermitian systems
- Non-Hermitian robust edge states in one-dimension: Anomalous localization and eigenspace condensation at exceptional points
- Vortex Pinning and Non-Hermitian Quantum Mechanics
- Observation of non-Hermitian topology and its bulk-edge correspondence in an active mechanical metamaterial
- Exact spectra, spin susceptibilities and order parameter of the quantum Heisenberg antiferromagnet on the triangular lattice
- An Introduction to Spontaneous Symmetry Breaking
- Why Decoherence has not Solved the Measurement Problem: A Response to P. W. Anderson
- Spontaneous Symmetry Breaking in Quantum Mechanics
- Quantum Dynamics in the Thermodynamic Limit
- Broken Time Translation Symmetry as a model for Quantum State Reduction
- A Nanoscale Experiment Measuring Gravity's Role in Breaking the Unitarity of Quantum Dynamics
- Spontaneous Symmetry Breaking and Decoherence in Superconductors
- Optical finite representation of the Lorentz group
- Coherence lifetimes of excitations in an atomic condensate due to the thin spectrum
- Exact Ground State of Lieb-Mattis Hamiltonian as a Superposition of Néel states
Cited by in corpus (4)
- Quantum state reduction of general initial states through spontaneous unitarity violation
- Colored noise driven unitarity violation causing dynamical quantum state reduction
- Continuous spontaneous localization as the white-noise limit of spontaneous unitarity violation
- New insights on the quantum-classical division in light of Collapse Models