%0 Journal Article
%T Spatial correlations in the dynamics of glassforming liquids: Experimental determination of their temperature dependence
%+ Laboratoire de Chimie Physique D'Orsay (LCPO)
%+ Systèmes Physiques Hors-équilibre, hYdrodynamique, éNergie  et compleXes (SPHYNX)
%+ Laboratoire Charles Coulomb (L2C)
%+ Institut de Physique Théorique - UMR CNRS 3681 (IPHT)
%+ Capital Fund Management (CFM)
%+ Service de physique de l'état condensé (SPEC - UMR3680)
%+ Laboratoire de Physique Théorique de la Matière Condensée (LPTMC)
%A Dalle-Ferrier, C.
%A Thibierge, C.
%A Alba-Simionesco, C.
%A Berthier, L.
%A Biroli, G.
%A Bouchaud, J.-P.
%A Ladieu, F.
%A L’hôte, D.
%A Tarjus, G.
%< avec comité de lecture
%@ 1539-3755
%J Physical Review E : Statistical, Nonlinear, and Soft Matter Physics
%I American Physical Society
%V 76
%P 041510
%8 2007
%D 2007
%R 10.1103/PhysRevE.76.041510
%Z Physics [physics]Journal articles
%X We use recently introduced three-point dynamic susceptibilities to obtain an experimental determination of the temperature evolution of the number of molecules N corr that are dynamically correlated during the structural relaxation of supercooled liquids. We first discuss in detail the physical content of three-point functions that relate the sensitivity of the averaged two-time dynamics to external control parameters such as temperature or density, as well as their connection to the more standard four-point dynamic susceptibility associated with dynamical heterogeneities. We then demonstrate that these functions can be experimentally determined with good precision. We gather available data to obtain the temperature dependence of N corr for a large number of supercooled liquids over a wide range of relaxation time scales from the glass transition up to the onset of slow dynamics. We find that N corr systematically grows when approaching the glass transition. It does so in a modest manner close to the glass transition, which is consistent with an activation-based picture of the dynamics in glassforming materials. For higher temperatures, there appears to be a regime where N corr behaves as a power-law of the relaxation time. Finally, we find that the dynamic response to density, while being smaller than the dynamic response to temperature, behaves similarly, in agreement with theoretical expectations.
%G English
%2 https://cea.hal.science/cea-01395180/document
%2 https://cea.hal.science/cea-01395180/file/PhysRevE_76_041510.pdf
%L cea-01395180
%U https://cea.hal.science/cea-01395180
%~ CEA
%~ UPMC
%~ CNRS
%~ UNIV-PSUD
%~ L2C
%~ LPTMC
%~ DSM-IPHT
%~ IRAMIS-SPEC
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%~ UNIV-PSUD-SACLAY
%~ UPMC_POLE_2
%~ MIPS
%~ UNIV-MONTPELLIER
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%~ UM-2015-2021
%~ ICPO