| Title |
Continuous-time random-walk approach to supercooled liquids: Self-part of the van Hove function and related quantities
|
|---|---|
| Published in |
The European Physical Journal E, June 2018
|
| DOI | 10.1140/epje/i2018-11680-1 |
| Pubmed ID | |
| Authors |
J. Helfferich, J. Brisch, H. Meyer, O. Benzerara, F. Ziebert, J. Farago, J. Baschnagel |
| Abstract |
From equilibrium molecular dynamics (MD) simulations of a bead-spring model for short-chain glass-forming polymer melts we calculate several quantities characterizing the single-monomer dynamics near the (extrapolated) critical temperature [Formula: see text] of mode-coupling theory: the mean-square displacement g0(t), the non-Gaussian parameter [Formula: see text] and the self-part of the van Hove function [Formula: see text] which measures the distribution of monomer displacements r in time t. We also determine these quantities from a continuous-time random walk (CTRW) approach. The CTRW is defined in terms of various probability distributions which we know from previous analysis. Utilizing these distributions the CTRW can be solved numerically and compared to the MD data with no adjustable parameter. The MD results reveal the heterogeneous and non-Gaussian single-particle dynamics of the supercooled melt near [Formula: see text]. In the time window of the early [Formula: see text] relaxation [Formula: see text] is large and [Formula: see text] is broad, reflecting the coexistence of monomer displacements that are much smaller ("slow particles") and much larger ("fast particles") than the average at time t, i.e. than [Formula: see text]. For large r the tail of [Formula: see text] is compatible with an exponential decay, as found for many glassy systems. The CTRW can reproduce the spatiotemporal dependence of [Formula: see text] at a qualitative to semiquantitative level. However, it is not quantitatively accurate in the studied temperature regime, although the agreement with the MD data improves upon cooling. In the early [Formula: see text] regime we also analyze the MD results for [Formula: see text] via the space-time factorization theorem predicted by ideal mode-coupling theory. While we find the factorization to be well satisfied for small r, both above and below [Formula: see text] , deviations occur for larger r comprising the tail of [Formula: see text]. The CTRW analysis suggests that single-particle "hops" are a contributing factor for these deviations. |
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Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Italy | 1 | 50% |
| Unknown | 1 | 50% |
Demographic breakdown
| Type | Count | As % |
|---|---|---|
| Scientists | 2 | 100% |
Mendeley readers
The data shown below were compiled from readership statistics for 10 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Unknown | 10 | 100% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Researcher | 2 | 20% |
| Other | 1 | 10% |
| Student > Master | 1 | 10% |
| Student > Ph. D. Student | 1 | 10% |
| Professor > Associate Professor | 1 | 10% |
| Other | 1 | 10% |
| Unknown | 3 | 30% |
| Readers by discipline | Count | As % |
|---|---|---|
| Physics and Astronomy | 3 | 30% |
| Biochemistry, Genetics and Molecular Biology | 1 | 10% |
| Chemical Engineering | 1 | 10% |
| Medicine and Dentistry | 1 | 10% |
| Engineering | 1 | 10% |
| Other | 0 | 0% |
| Unknown | 3 | 30% |
Attention Score in Context
This research output has an Altmetric Attention Score of 1. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 26 June 2018.
All research outputs
#15,821,622
of 23,498,099 outputs
Outputs from The European Physical Journal E
#395
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#211,541
of 331,368 outputs
Outputs of similar age from The European Physical Journal E
#11
of 17 outputs
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