%0 Journal Article
%T Unexpected drop of dynamical heterogeneities in colloidal suspensions approaching the jamming transition
%+ Laboratoire des colloïdes, verres et nanomatériaux (LCVN)
%A Ballesta, Pierre
%A Duri, Agnes
%A Cipelletti, Luca
%Z ACI JC2076 European MCRTN ‘Arrested matter' (MRTN-CT-2003-504712) European NoE ‘SoftComp' (NMP3-CT-2004-502235)
%Z 1st version originally submitted to Nature Physics. See the Nature Physics website fro the final, published version
%< avec comité de lecture
%@ 1745-2473
%J Nature Physics
%I Nature Publishing Group
%V 4
%N 7
%P 550-554
%8 2008-06-22
%D 2008
%Z 0807.0281
%R 10.1038/nphys1000
%K Glass transition
%K jamming
%K dynamical heterogeneity
%K diffusing wave spectroscopy
%Z Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft]Journal articles
%X As the glass (in molecular fluids\cite{Donth}) or the jamming (in colloids and grains\cite{LiuNature1998}) transitions are approached, the dynamics slow down dramatically with no marked structural changes. Dynamical heterogeneity (DH) plays a crucial role: structural relaxation occurs through correlated rearrangements of particle ``blobs'' of size $\xi$\cite{WeeksScience2000,DauchotPRL2005,Glotzer,Ediger}. On approaching these transitions, $\xi$ grows in glass-formers\cite{Glotzer,Ediger}, colloids\cite{WeeksScience2000,BerthierScience2005}, and driven granular materials\cite{KeysNaturePhys2007} alike, strengthening the analogies between the glass and the jamming transitions. However, little is known yet on the behavior of DH very close to dynamical arrest. Here, we measure in colloids the maximum of a ``dynamical susceptibility'', $\chi^*$, whose growth is usually associated to that of $\xi$\cite{LacevicPRE}. $\chi^*$ initially increases with volume fraction $\varphi$, as in\cite{KeysNaturePhys2007}, but strikingly drops dramatically very close to jamming. We show that this unexpected behavior results from the competition between the growth of $\xi$ and the reduced particle displacements associated with rearrangements in very dense suspensions, unveiling a richer-than-expected scenario.
%G English
%2 https://hal.science/hal-00292570/document
%2 https://hal.science/hal-00292570/file/1stVersionForCondmat.pdf
%L hal-00292570
%U https://hal.science/hal-00292570
%~ CNRS
%~ UNIV-MONTP2
%~ LCVN
%~ UNIV-MONTPELLIER
%~ INRAE
%~ UM1-UM2