Spin-flop multicritical points in systems with random fields and in spin glasses
- 1 October 1978
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review B
- Vol. 18 (7), 3328-3336
- https://doi.org/10.1103/physrevb.18.3328
Abstract
Mean-field theory and renormalization-group arguments are used to study the phase diagram of an anisotropic -component -dimensional magnetic system with a uniaxially random magnetic field. The resulting phase diagram is shown to be very similar to that of anisotropic antiferromagnets in a uniform field: For small random fields, the system orders along the direction of uniaxial anisotropy, with exponents which are related to those of nonrandom Ising systems in dimensions. For larger random fields, parallel to the direction of uniaxial anisotropy, the transverse spin components order, with exponents which are unaffected by the random field. The two regions are separated by a spin-flop first-order line, by an intermediate "mixed" phase, and by a tetracritical (or bicritical) point. The exponents at this multicritical point are shown to coincide, near , with those of the random-field Ising model. This phase diagram is shown to describe the behavior of random-site spin glasses in a uniform magnetic field. Other types of anisotropic random fields, related experimental realizations and other generalizations are also mentioned. Although some of the quantitative results are found only near , qualitative results are believed to apply at as well.
Keywords
This publication has 33 references indexed in Scilit:
- Tricritical points in systems with random fieldsPhysical Review B, 1978
- Spin-glass and related orderings in quenched random-spin systemsPhysical Review B, 1977
- Critical properties of a simple soluble spin glass modelSolid State Communications, 1976
- Comments upon the Mattis model of a spin glassPhysics Letters A, 1976
- Solvable spin systems with random interactionsPhysics Letters A, 1976
- Bicritical and tetracritical points in anisotropic antiferromagnetic systemsPhysical Review B, 1976
- Theory of spin glassesJournal of Physics F: Metal Physics, 1975
- Renormalization-Group Analysis of Bicritical and Tetracritical PointsPhysical Review Letters, 1974
- Spin Flop, Supersolids, and Bicritical and Tetracritical PointsPhysical Review Letters, 1974
- The theory of equilibrium critical phenomenaReports on Progress in Physics, 1967