Pattern formation in the framework of the continuum theory of dislocations

2003 ◽  
Vol 67 (9) ◽  
Author(s):  
Jan Kratochvíl ◽  
Radan Sedláček
2015 ◽  
Vol 11 (4) ◽  
pp. 527-543 ◽  
Author(s):  
Nikolay A. Kudryashov ◽  
Mikhail V. Skachkov

Purpose – The purpose of this paper is to investigate the influence of ion-flow parameters on surface topography and making numerical simulation at the times when the process of surface erosion becomes strongly nonlinear. Design/methodology/approach – The base of the mathematical model of target ion-sputtering is nonlinear evolutionary equation in which the erosion velocity dependence on ion flux is evaluated by means of a Monte Carlo method. The difference between this equation and the one of continuum theory is that the ion flux is not smooth function. Instead, it is a set of separate incident ions. Findings – Some simulations with using independent random points of arrival for the incident ions leads to results uncorrelated with the continuum model at early times. The ripples are not quite developed or observed. This phenomenon is explained by random fluctuations of the target sputtering depth. Sufficiently big values of the random fluctuations destroy the ripple structure on target surface. The simulation with using equally distributed sequence (Holton sequence) of points of arrival for the incident ions leads to results well correlated with the continuum model. Originality/value – The discrete model which goes into the equation of continuum theory within the appropriate asymptotic limit has been proposed. The discretization parameters influence on surface morphology formation has been studied. This paper may be interesting to researchers making the theoretical and numerical analysis of pattern formation on plane target surfaces undergoing ion-beam sputtering.


Nature ◽  
10.1038/16891 ◽  
1999 ◽  
Vol 397 (6717) ◽  
pp. 333-335 ◽  
Author(s):  
Eran Sharon ◽  
Jay Fineberg

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Dionysios Anninos ◽  
Beatrix Mühlmann

Abstract We explore the conjectured duality between a class of large N matrix integrals, known as multicritical matrix integrals (MMI), and the series (2m − 1, 2) of non-unitary minimal models on a fluctuating background. We match the critical exponents of the leading order planar expansion of MMI, to those of the continuum theory on an S2 topology. From the MMI perspective this is done both through a multi-vertex diagrammatic expansion, thereby revealing novel combinatorial expressions, as well as through a systematic saddle point evaluation of the matrix integral as a function of its parameters. From the continuum point of view the corresponding critical exponents are obtained upon computing the partition function in the presence of a given conformal primary. Further to this, we elaborate on a Hilbert space of the continuum theory, and the putative finiteness thereof, on both an S2 and a T2 topology using BRST cohomology considerations. Matrix integrals support this finiteness.


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