42,415 research outputs found
Faceted anomalous scaling in the epitaxial growth of semiconductor films
We apply the generic dynamical scaling theory (GDST) to the surfaces of CdTe
polycrystalline films grown in glass substrates. The analysed data were
obtained with a stylus profiler with an estimated resolution lateral resolution
of m. Both real two-point correlation function and power spectrum
analyses were done. We found that the GDST applied to the surface power spectra
foresees faceted morphology in contrast with the self-affine surface indicated
by the local roughness exponent found via the height-height correlation
function. This inconsistency is explained in terms of convolution effects
resulting from the finite size of the probe tip used to scan the surfaces. High
resolution AFM images corroborates the predictions of GDST.Comment: to appear in Europhysics Letter
First- and second-order phase transitions in Ising models on small world networks, simulations and comparison with an effective field theory
We perform simulations of random Ising models defined over small-world
networks and we check the validity and the level of approximation of a recently
proposed effective field theory. Simulations confirm a rich scenario with the
presence of multicritical points with first- or second-order phase transitions.
In particular, for second-order phase transitions, independent of the dimension
d_0 of the underlying lattice, the exact predictions of the theory in the
paramagnetic regions, such as the location of critical surfaces and correlation
functions, are verified. Quite interestingly, we verify that the
Edwards-Anderson model with d_0=2 is not thermodynamically stable under graph
noise.Comment: 12 pages, 12 figures, 1 tabl
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