Infinite family of persistence exponents for interface fluctuations

TL;DR

This study reveals an infinite set of persistence exponents characterizing equilibrium step fluctuations, supported by experimental data on metal surfaces and theoretical models for different kinetic regimes.

Contribution

It introduces the concept of an infinite family of persistence exponents for interface fluctuations, combining experimental observations with theoretical analysis.

Findings

Multiple independent persistence exponents identified

Experimental validation on Al/Si(111) and Ag(111) surfaces

Theoretical models explain temperature-dependent fluctuation behavior

Abstract

We show experimentally and theoretically that the persistence of large deviations in equilibrium step fluctuations is characterized by an infinite family of independent exponents. These exponents are obtained by carefully analyzing dynamical experimental images of Al/Si(111) and Ag(111) equilibrium steps fluctuating at high (970K) and low (320K) temperatures respectively, and by quantitatively interpreting our observations on the basis of the corresponding coarse-grained discrete and continuum theoretical models for thermal surface step fluctuations under attachment/detachment (``high-temperature'') and edge-diffusion limited kinetics (``low-temperature'') respectively.