Effective Spin-1/2 Description of Transverse-Field-Induced Random Fields in Dipolar Spin Glasses with Strong Single-Ion Anisotropy

Abstract

We present analytical and numerical evidence for the validity of an effective S=1/2 approach to the description of random field generation in S>=1, and especially in an S=1, dipolar spin glass models with strong uniaxial Ising anisotropy and subject to weak external magnetic field Bx transverse to the Ising direction. Explicitely Bx-dependent random fields are shown to naturally emerge in the effective low-energy description of a microscopic S=1 toy model. We discuss our results in relation to recent theoretical studies pertaining to the topic of Bx-induced random fields in the LiHo${}_x$Y${}_{1-x}$F${}_4$ magnetic materials with the Ho${}^{3+}$ Ising moments subject to a transverse field. We show that the S_{eff}=1/2 approach is able to capture both the qualitative and quantitative aspects of the physics at small Bx, giving results that agree with those obtained using conventional second order perturbation theory.

9 pages. 4 eps figures

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• Absence of an Almeida-Thouless line in Three-Dimensional Spin Glasses
• Ferromagnet in a continuously tuneable random field
• $\mathrm{LiH}{\mathrm{o}}_{\mathrm{x}}{\mathrm{Y}}_{1-\mathrm{x}}{\mathrm{F}}_4$ as a random field Ising ferromagnet
• Absence of Conventional Spin-Glass Transition in the Ising Dipolar System LiHo_xY_{1-x}F_4
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• Quantum Projection in an Ising Spin Liquid
• Quantum spin glass in anisotropic dipolar systems

Cited by in corpus (5)

• Quantum and Classical Glass Transitions in $LiH{o}_x{Y}_{1-x}{F}_4$
• The low-$T$ phase diagram of $\mathrm{LiH}{\mathrm{o}}_{\mathrm{x}}{\mathrm{Y}}_{1-\mathrm{x}}{\mathrm{F}}_4$
• Low-temperature properties of the dilute dipolar magnet LiHo_xY_(1-x)F_4
• Perturbative Quantum Monte Carlo Study of LiHoF4 in a Transverse Magnetic Field
• Assessment of the RE(OH)3 Ising-like Magnetic Materials as Possible Candidates for the Study of Transverse-Field-Induced Quantum Phase Transitions