135 research outputs found
The Merged Potts-Clock Model: Algebraic and Conventional Multistructured Multicritical Orderings in Two and Three Dimensions
A spin system is studied, with simultaneous permutation-symmetric Potts and
spin-rotation-symmetric clock interactions, in spatial dimensions d=2 and 3.
The global phase diagram is calculated from the renormalizaton-group solution
with the recently improved (spontaneous first-order detecting) Migdal-Kadanoff
approximation or, equivalently, with hierarchical lattices with the inclusion
of effective vacancies. Five different ordered phases are found: conventionally
ordered ferromagnetic, quadrupolar, antiferromagnetic phases and algebraically
ordered antiferromagnetic, antiquadrupolar phases. These five different ordered
phases and the disordered phase are mutually bounded by first- and second-order
phase transitions, themselves delimited by multicritical points: inverted
bicritical, zero-temperature bicritical, tricritical, second-order bifurcation,
and zero-temperature highly degenerate multicritical points. One rich phase
diagram topology exhibits all of these phenomena.Comment: 7 pages, 3 figures, 1 tabl
Nematic Phase of the n-Component Cubic-Spin Spin Glass in d=3: Liquid-Crystal Phase in a Dirty Magnet
A nematic phase, previously seen in the d=3 classical Heisenberg spin-glass
system, occurs in the n-component cubic-spin spin-glass system, between the
low-temperature spin-glass phase and the high temperature disordered phase, for
number of components n >= 3, in spatial dimension d=3, thus constituting a
liquid-crystal phase in a dirty (quenched-disordered) magnet. This result is
obtained from renormalization-group calculations that are exact on the
hierarchical lattice and, equivalently, approximate on the cubic spatial
lattice. The nematic phase completely intervenes between the spin-glass phase
and the disordered phase. The Lyapunov exponents of the spin-glass chaos are
calculated from n=1 up to n=12 and show odd-even oscillations with respect to
n.Comment: 4 pages, 5 figure
Driven and Non-Driven Surface Chaos in Spin-Glass Sponges
A spin-glass system with a smooth or fractal outer surface is studied by
renormalization-group theory, in bulk spatial dimension d=3. Independently
varying the surface and bulk random-interaction strengths, phase diagrams are
calculated. The smooth surface does not have spin-glass ordering in the absence
of bulk spin-glass ordering and always has spin-glass ordering when the bulk is
spin-glass ordered. With fractal (d>2) surfaces, a sponge is obtained and has
surface spin-glass ordering also in the absence of bulk spin-glass ordering.
The phase diagram has the only-surface-spin-glass ordered phase, the bulk and
surface spin-glass ordered phase, and the disordered phase, and a special
multicritical point where these three phases meet. All spin-glass phases have
distinct chaotic renormalization-group trajectories, with distinct Lyapunov and
runaway exponents which we have calculated.Comment: 4 pages, 3 figure
Modeling, analysis, and screening of cyclic pressure pulsing with nitrogen in hydraulically fractured wells
Root resorption during orthodontic treatment with self-ligating or conventional brackets: a systematic review and meta-analysis
Quantitative analysis of S. mutans and S. sobrinus cultivated independently and adhered to polished orthodontic composite resins
Effect of etching and light-curing time on the shear bond strength of a resin-modified glass ionomer cement
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