skip to main content

SciTech ConnectSciTech Connect

Title: Communication: Probing anomalous diffusion in frequency space

Anomalous diffusion processes are usually detected by analyzing the time-dependent mean square displacement of the diffusing particles. The latter evolves asymptotically as W(t) ∼ 2D{sub α}t{sup α}, where D{sub α} is the fractional diffusion constant and 0 < α < 2. In this article we show that both D{sub α} and α can also be extracted from the low-frequency Fourier spectrum of the corresponding velocity autocorrelation function. This offers a simple method for the interpretation of quasielastic neutron scattering spectra from complex (bio)molecular systems, in which subdiffusive transport is frequently encountered. The approach is illustrated and validated by analyzing molecular dynamics simulations of molecular diffusion in a lipid POPC bilayer.
Authors:
 [1] ;  [2] ;  [1] ;  [2] ;  [2]
  1. Centre de Biophys. Moléculaire, CNRS, Rue Charles Sadron, 45071 Orléans (France)
  2. (France)
Publication Date:
OSTI Identifier:
22493242
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 143; Journal Issue: 19; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; COMPLEXES; COMPUTERIZED SIMULATION; DIFFUSION; LAYERS; LIPIDS; MOLECULAR DYNAMICS METHOD; PARTICLES; PROBES; QUASI-ELASTIC SCATTERING; TIME DEPENDENCE; VELOCITY