Fifth-order susceptibility unveils growth of thermodynamic amorphous order in glass-formers

S. Albert (1) , T. Bauer (2, 3) , M. Michl (3) , G. Biroli (4, 5) , P. Bouchaud (6) , A. Loidl (3) , P. Lunkenheimer (3) , R. Tourbot (1) , C. Wiertel-Gasquet (1) , F. Ladieu (1)

1 SPHYNX - Systèmes Physiques Hors-équilibre, hYdrodynamique, éNergie et compleXes
2 Institute for Machine Tools and Industrial Management
3 Experimentalphysik V, Center for Electronic Correlations and Magnetism, Institute for Physics
4 LPS - Laboratoire de Physique Statistique de l'ENS
5 IPHT - Institut de Physique Théorique - UMR CNRS 3681
6 Capital Fund Management

Glasses are ubiquitous in daily life and technology. However the microscopic mechanisms generating this state of matter remain subject to debate: Glasses are considered either as merely hyper-viscous liquids or as resulting from a genuine thermodynamic phase transition towards a rigid state. We show that third and fifth order susceptibilities provide a definite answer to this longstanding controversy. Performing the corresponding high-precision nonlinear dielec-tric experiments for supercooled glycerol and propylene carbonate, we find strong support for theories based upon thermodynamic amorphous order. Moreover, when lowering temperature, we find that the growing transient domains are compact – that is their fractal dimension d f = 3. The glass transition may thus represent a class of critical phenomena different from canonical second-order phase transitions for which d f < 3.

Domains: Physics [physics]

S. Albert, T. Bauer, M. Michl, G. Biroli, P. Bouchaud, et al.. Fifth-order susceptibility unveils growth of thermodynamic amorphous order in glass-formers. Science, 2016, 352 (6291), pp.1308 - 1311. ⟨10.1126/science.aaf3182⟩. ⟨cea-01394421⟩