4,571 research outputs found
Persistence of Kardar-Parisi-Zhang Interfaces
The probabilities that a growing Kardar-Parisi-Zhang interface
remains above or below the mean height in the time interval are
shown numerically to decay as with and . Bounds on are
derived from the height autocorrelation function under the assumption of
Gaussian statistics. The autocorrelation exponent for a
--dimensional interface with roughness and dynamic exponents and
is conjectured to be . For a recently proposed
discretization of the KPZ equation we find oscillatory persistence
probabilities, indicating hidden temporal correlations.Comment: 4 pages, 3 figures, uses revtex and psfi
Kinetics of step bunching during growth: A minimal model
We study a minimal stochastic model of step bunching during growth on a
one-dimensional vicinal surface. The formation of bunches is controlled by the
preferential attachment of atoms to descending steps (inverse Ehrlich-Schwoebel
effect) and the ratio of the attachment rate to the terrace diffusion
coefficient. For generic parameters () the model exhibits a very slow
crossover to a nontrivial asymptotic coarsening exponent .
In the limit of infinitely fast terrace diffusion () linear coarsening
( = 1) is observed instead. The different coarsening behaviors are
related to the fact that bunches attain a finite speed in the limit of large
size when , whereas the speed vanishes with increasing size when .
For an analytic description of the speed and profile of stationary
bunches is developed.Comment: 8 pages, 10 figure
Equilibrium of anchored interfaces with quenched disordered growth
The roughening behavior of a one-dimensional interface fluctuating under
quenched disorder growth is examined while keeping an anchored boundary. The
latter introduces detailed balance conditions which allows for a thorough
analysis of equilibrium aspects at both macroscopic and microscopic scales. It
is found that the interface roughens linearly with the substrate size only in
the vicinity of special disorder realizations. Otherwise, it remains stiff and
tilted.Comment: 6 pages, 3 postscript figure
Damping of Oscillations in Layer-by-Layer Growth
We present a theory for the damping of layer-by-layer growth oscillations in
molecular beam epitaxy. The surface becomes rough on distances larger than a
layer coherence length which is substantially larger than the diffusion length.
The damping time can be calculated by a comparison of the competing roughening
and smoothening mechanisms. The dependence on the growth conditions,
temperature and deposition rate, is characterized by a power law. The
theoretical results are confirmed by computer simulations.Comment: 19 pages, RevTex, 5 Postscript figures, needs psfig.st
An Exactly Solved Model of Three Dimensional Surface Growth in the Anisotropic KPZ Regime
We generalize the surface growth model of Gates and Westcott to arbitrary
inclination. The exact steady growth velocity is of saddle type with principal
curvatures of opposite sign. According to Wolf this implies logarithmic height
correlations, which we prove by mapping the steady state of the surface to
world lines of free fermions with chiral boundary conditions.Comment: 9 pages, REVTEX, epsf, 3 postscript figures, submitted to J. Stat.
Phys, a wrong character is corrected in eqs. (31) and (32
Heilige Andacht : Religioso
https://digitalcommons.library.umaine.edu/mmb-ps/3597/thumbnail.jp
Short-time scaling behavior of growing interfaces
The short-time evolution of a growing interface is studied within the
framework of the dynamic renormalization group approach for the
Kadar-Parisi-Zhang (KPZ) equation and for an idealized continuum model of
molecular beam epitaxy (MBE). The scaling behavior of response and correlation
functions is reminiscent of the ``initial slip'' behavior found in purely
dissipative critical relaxation (model A) and critical relaxation with
conserved order parameter (model B), respectively. Unlike model A the initial
slip exponent for the KPZ equation can be expressed by the dynamical exponent
z. In 1+1 dimensions, for which z is known exactly, the analytical theory for
the KPZ equation is confirmed by a Monte-Carlo simulation of a simple ballistic
deposition model. In 2+1 dimensions z is estimated from the short-time
evolution of the correlation function.Comment: 27 pages LaTeX with epsf style, 4 figures in eps format, submitted to
Phys. Rev.
Comparison of mercury in atmospheric deposition and in Illinois and USA soils
International audienceIt has been reported that most mercury (Hg) in USA soils is from atmospheric Hg deposition, mostly from anthropogenic sources. This paper compares the rates of atmospheric Hg deposition to amounts of Hg in Illinois and USA soils. The amounts of Hg in these soils are too great to be attributed mainly to anthropogenic atmospheric Hg deposition. Keywords: mercury, atmospheric deposition, soil, geology, Illinois, US
Interfaces with a single growth inhomogeneity and anchored boundaries
The dynamics of a one dimensional growth model involving attachment and
detachment of particles is studied in the presence of a localized growth
inhomogeneity along with anchored boundary conditions. At large times, the
latter enforce an equilibrium stationary regime which allows for an exact
calculation of roughening exponents. The stochastic evolution is related to a
spin Hamiltonian whose spectrum gap embodies the dynamic scaling exponent of
late stages. For vanishing gaps the interface can exhibit a slow morphological
transition followed by a change of scaling regimes which are studied
numerically. Instead, a faceting dynamics arises for gapful situations.Comment: REVTeX, 11 pages, 9 Postscript figure
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