617 research outputs found
Hidden Order in
We review current attempts to characterize the underlying nature of the
hidden order in . A wide variety of experiments point to the
existence of two order parameters: a large primary order parameter of unknown
character which co-exists with secondary antiferromagnetic order. Current
theories can be divided into two groups determined by whether or not the
primary order parameter breaks time-reversal symmetry. We propose a series of
experiments designed to test the time-reversal nature of the underlying primary
order in and to characterize its local single-ion physics
Contrasting the magnetic response between magnetic-glass and reentrant spin-glass
Magnetic-glass is a recently identified phenomenon in various classes of
magnetic systems undergoing a first order magnetic phase transition. We shall
highlight here a few experimentally determined characteristics of
magnetic-glass and the relevant set of experiments, which will enable to
distinguish a magnetic-glass unequivocally from the well known phenomena of
spin-glass and reentrant spin-glass.Comment: 10 pages and 4 figures. The preprint has been amended after taking
care of various typographical errors, some errors in Figs.2 and 4 and with
the addition of some new references. This version has been accepted for
publication in Physical Review
Spin-chirality decoupling in the one-dimensional Heisenberg spin glass with long-range power-law interactions
We study the issue of the spin-chirality decoupling/coupling in the ordering
of the Heisenberg spin glass by performing large-scale Monte Carlo simulations
on a one-dimensional Heisenberg spin-glass model with a long-range power-law
interaction up to large system sizes. We find that the spin-chirality
decoupling occurs for an intermediate range of the power-law exponent.
Implications to the corresponding -dimensional short-range model is
discussed.Comment: 5 pages, 4 figures, to appear in Physical Review Letter
Nonlinear and spin-glass susceptibilities of three site-diluted systems
The nonlinear magnetic and spin-glass susceptibilities
in zero applied field are obtained, from tempered Monte Carlo simulations, for
three different spin glasses (SGs) of Ising spins with quenched site disorder.
We find that the relation ( is the temperature),
which holds for Edwards-Anderson SGs, is approximately fulfilled in
canonical-like SGs. For nearest neighbor antiferromagnetic interactions, on a
0.4 fraction of all sites in fcc lattices, as well as for spatially disordered
Ising dipolar (DID) systems, and appear to diverge in
the same manner at the critical temperature . However, is
smaller than by over two orders of magnitude in the diluted fcc
system. In DID systems, is very sensitive to the systems
aspect ratio. Whereas near , varies by approximately a
factor of 2 as system shape varies from cubic to long-thin-needle shapes,
sweeps over some four decades.Comment: 7 pages, 7 figure
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