Random-field-induced disordering mechanism in a disordered ferromagnet: Between the Imry-Ma and the standard disordering mechanism

Abstract

Random fields disorder Ising ferromagnets by aligning single spins in the direction of the random field in three space dimensions, or by flipping large ferromagnetic domains at dimensions two and below. While the former requires random fields of typical magnitude similar to the interaction strength, the latter Imry-Ma mechanism only requires infinitesimal random fields. Recently, it has been shown that for dilute anisotropic dipolar systems a third mechanism exists, where the ferromagnetic phase is disordered by finite-size glassy domains at a random field of finite magnitude that is considerably smaller than the typical interaction strength. Using large-scale Monte Carlo simulations and zero-temperature numerical approaches, we show that this mechanism applies to disordered ferromagnets with competing short-range ferromagnetic and antiferromagnetic interactions, suggesting its generality in ferromagnetic systems with competing interactions and an underlying spin-glass phase. A finite-size-scaling analysis of the magnetization distribution suggests that the transition might be first order.

12 pages, 7 figures, 4 tables

References in corpus (20)

• Universality in three-dimensional Ising spin glasses: A Monte Carlo study
• Absence of an Almeida-Thouless line in Three-Dimensional Spin Glasses
• Study of the de Almeida-Thouless line using power-law diluted one-dimensional Ising spin glasses
• Induced Random Fields in the LiHo${}_x$Y${}_{1-x}$F${}_4$ Quantum Ising Magnet in a Transverse Magnetic Field
• Ferromagnet in a continuously tuneable random field
• Behavior of Ising Spin Glasses in a Magnetic Field
• $\mathrm{LiH}{\mathrm{o}}_{\mathrm{x}}{\mathrm{Y}}_{1-\mathrm{x}}{\mathrm{F}}_4$ as a random field Ising ferromagnet
• Microcanonical Approach to the Simulation of First-Order Phase Transitions
• The low-$T$ phase diagram of $\mathrm{LiH}{\mathrm{o}}_{\mathrm{x}}{\mathrm{Y}}_{1-\mathrm{x}}{\mathrm{F}}_4$
• The 3D +-J Ising model at the ferromagnetic transition line
• Spin Glass Transition at Nonzero Temperature in a Disordered Dipolar Ising System: The Case of LiHoxY{1-x}F4
• Improved extremal optimization for the Ising spin glass
• Evidence of non-mean-field-like low-temperature behavior in the Edwards-Anderson spin-glass model
• First order transition in a three dimensional disordered system
• Existence of a Thermodynamic Spin-Glass Phase in the Zero-Concentration Limit of Anisotropic Dipolar Systems
• Some considerations of finite dimensional spin glasses
• Ageing at the Spin-Glass/Ferromagnet Transition: Monte Carlo Simulation using GPUs
• The cumulative overlap distribution function in realistic spin glasses
• Numerical test of the Cardy-Jacobsen conjecture in the site-diluted Potts model in three dimensions
• Random-field Ising model: Insight from zero-temperature simulations