Anisotropic spatially heterogeneous dynamics on the alpha and beta relaxation time scales studied via a four-point correlation function Export

@article{citeulike:5008177, abstract = {We examine the anisotropy of a four-point correlation function G4(,;t) and its associated structure factor S4(,;t) calculated using Brownian dynamics computer simulations of a model glass forming system. These correlation functions measure the spatial correlations of the relaxation of different particles. We examine the time and temperature dependences of the anisotropy in both functions. We find that the anisotropy is strongest at nearest-neighbor distances at time scales corresponding to the peak of the non-Gaussian parameter 2(t)=3r4(t)/[5r2(t)2]\−1 but is still pronounced around the relaxation time. We find that the structure factor S4(,;t) is anisotropic even for the lowest wave vector accessible in our simulation, suggesting that our system (and other systems commonly used in computer simulations) may be too small to extract the 0 limit of the structure factor. We find that the determination of a dynamic correlation length from S4(,;t) is influenced by the anisotropy. We extract an effective anisotropic dynamic correlation length from the small q behavior of S4(,;t).}, author = {Flenner, Elijah and Szamel, Grzegorz}, citeulike-article-id = {5008177}, citeulike-linkout-0 = {http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PLEEE8000079000005051502000001&idtype=cvips&gifs=yes}, citeulike-linkout-1 = {http://link.aps.org/abstract/PRE/v79/e051502}, citeulike-linkout-2 = {http://dx.doi.org/10.1103/PhysRevE.79.051502}, doi = {10.1103/PhysRevE.79.051502}, journal = {Physical Review E (Statistical, Nonlinear, and Soft Matter Physics)}, keywords = {chi4, dynahetero, glass, simulation}, number = {5}, pages = {051502+}, posted-at = {2009-06-29 09:01:16}, priority = {0}, publisher = {APS}, title = {Anisotropic spatially heterogeneous dynamics on the alpha and beta relaxation time scales studied via a four-point correlation function}, url = {http://dx.doi.org/10.1103/PhysRevE.79.051502}, volume = {79}, year = {2009} }

TY - JOUR ID - citeulike:5008177 L3 - citeulike-article-id:5008177 N2 - We examine the anisotropy of a four-point correlation function G4(,;t) and its associated structure factor S4(,;t) calculated using Brownian dynamics computer simulations of a model glass forming system. These correlation functions measure the spatial correlations of the relaxation of different particles. We examine the time and temperature dependences of the anisotropy in both functions. We find that the anisotropy is strongest at nearest-neighbor distances at time scales corresponding to the peak of the non-Gaussian parameter 2(t)=3r4(t)/[5r2(t)2]−1 but is still pronounced around the relaxation time. We find that the structure factor S4(,;t) is anisotropic even for the lowest wave vector accessible in our simulation, suggesting that our system (and other systems commonly used in computer simulations) may be too small to extract the 0 limit of the structure factor. We find that the determination of a dynamic correlation length from S4(,;t) is influenced by the anisotropy. We extract an effective anisotropic dynamic correlation length from the small q behavior of S4(,;t). IS - 5 JF - Physical Review E (Statistical, Nonlinear, and Soft Matter Physics) TI - Anisotropic spatially heterogeneous dynamics on the alpha and beta relaxation time scales studied via a four-point correlation function PB - APS VL - 79 SP - 051502 KW - chi4 KW - dynahetero KW - glass KW - simulation AU - Flenner, Elijah AU - Szamel, Grzegorz PY - 2009/// UR - http://dx.doi.org/10.1103/PhysRevE.79.051502 ER -