AVS 50th International Symposium
    Surface Science Wednesday Sessions
       Session SS-WeP

Paper SS-WeP9
Persistence Exponent for Terrace-Diffusion Limited Step Fluctuations: Numerical Simulation@footnote 1@

Wednesday, November 5, 2003, 11:00 am, Room Hall A-C

Session: Poster Session
Presenter: H. Gebremariam, University of Maryland, College Park
Authors: H. Gebremariam, University of Maryland, College Park
C. Dasgupta, University of Maryland, College Park
T.L. Einstein, University of Maryland, College Park
Correspondent: Click to Email
The strength of the step-step repulsion, one of the 3 key parameters of the step continuum model, is known to influence many properties of a vicinal surfaces. Motivated by experiments at Maryland on Ag(111) and Pb(111)@footnote 2@ and on Al/Si(111),@footnote 3@ we gauge the impact these interactions on the persistence exponent @theta@. (Here the steady-state persistence probability p(t) ~ t^(-@theta@) is the probability that a fluctuating step has not crossed a chosen rough initial position by time t.@footnote 4@) According to simple scaling based on Langevin arguments, @theta@ should be (1/2)[1+1/z] for evaporation-condensation (z=2) and (1/2)[1+3/(4z)] for periphery diffusion dynamics (z = 4).@footnote 4@ To investigate whether either of these relations also holds for terrace-diffusion-limited (TD) dynamics (for which z=3), we perform Monte Carlo simulations for an SOS model similar to that used for earlier investigations of step fluctuations.@footnote 5@ @FootnoteText@ @footnote 1@Work at UM supported by NSF Grants MRSEC DMR 00-80008 and EEC-0085604. @footnote 2@D.B. Dougherty et al., Surface Sci., in press [doi:10.1016/S0039-6028(03)00017-7]. @footnote 3@D.B. Dougherty et al., Phys. Rev. Lett. 89 (2002) 136102.@footnote 4@J. Krug et al., Phys. Rev. E 56 (1997 2702.@footnote 5@ N. C. Bartelt et al., Surface Sci. 312 (1994) 411.