Eur. Phys. J. E (2014) 37: 46
https://doi.org/10.1140/epje/i2014-14046-9

Regular Article

New conserved structural fields for supercooled liquids

Institut Charles Sadron, Université de Strasbourg, CNRS UPR 22, 23 rue du Loess, BP 84047, 67034, Strasbourg Cedex 2, France

^* e-mail: jean.farago@ics-cnrs.unistra.fr

Received: 30 September 2013
Revised: 17 March 2014
Accepted: 12 May 2014
Published online: 6 June 2014

Abstract

By considering Voronoi tessellations of the configurations of a fluid, we propose two new conserved fields, which provide structural information not fully accounted for by the usual 2-point density correlation functions. One of these fields is scalar and associated with the volume of the Voronoi cell, whereas the other one, termed the “geometric polarisation”, is vectorial and related to the local anisotropy of the configurations. We study the static and dynamical properties of these fields in the supercooled regime of a model glass-forming liquid. We show that the geometric polarisation is statically correlated to the force field, but contrary to it develops a plateau regime when the temperature is lowered. This different relaxation is related to the cage effect in glass-forming liquids, which prevents a complete relaxation of the shape of the cage around particle on intermediate time scales.