Fluctuation induced first-order phase transitions in a dipolar Ising ferromagnetic slab

Fluctuation Induced First Order Phase Transitions

We study a U(N) × U(N) symmetric scalar field model in four and three dimensions. First, using our data in four dimensions in the weak coupling region, we demonstrate explicitly that the observed first order phase transition is induced by quantum fluctuations. Next, based on the renormalization group and our new simulation results in three dimensions we argue that even if the UA(1) symmetry is ...

Degeneracy and strong fluctuation-induced first-order phase transition in the dipolar pyrochlore antiferromagnet

We show that a continuous set of degenerate critical soft modes strongly enhances the first-order character of a fluctuation-induced first-order transition in the pyrochlore dipolar Heisenberg antiferromagnet. Such a degeneracy seems essential to explain the strong first-order transition recently observed in Gd2Sn2O7. We present some evidence from Monte Carlo simulations and a perturbative reno...

Fluctuation-Induced First Order Phase Transitions in Type-1.5 Superconductors in Zero External Field

Langevin dynamics of fluctuation-induced first-order phase transitions: Self-consistent Hartree approximation

The Langevin dynamics of a system with a scalar-order parameter exhibiting a fluctuation-induced firstorder phase transition is solved within the self-consistent Hartree approximation. Competition between interactions on short and long length scales gives rise to spatial modulations in the order parameter, such as stripes in 2d and lamellae in 3d. We show that when the time scale of observation...

Noise - induced first - order phase transitions in chaotic brain activity

Brain electrical activity in animals during normal behaviors has aperiodic wave forms that suggest its origin in chaotic dynamics. Attempts using low-dimensional, deterministic chaotic models to prove that pulse trains and electroencephalographic (EEG) waves are chaotic have not succeeded. The assumptions of autonomy, stationarity, and noise-free operation that are needed to define the attracto...