Dresden 2009 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 34: Liquid and Amorphous Metals I

MM 34.2: Vortrag

Mittwoch, 25. März 2009, 15:00–15:15, IFW D

Supercooled and glass-forming liquids as Skyrmionic textures — •Andrei A. Leonov^1,2, U.K. Rößler¹, and A.N. Bogdanov¹ — ¹IFW Dresden — ²Donetsk Institute for Physics and Technology

The concept of Skyrmionic textures in chiral magnetic systems [1] has been extended to continuum models for glass-forming liquids. These models describe the frustrated tiling of space by incompatible locally preferred clusters within a generalized elastic theory. The field theory for the local order-parameter includes antisymmetric couplings derived from the decurving of ideal template units into flat space[2]. As a qualitative new feature, we propose a softened modulus of the local intensity of the order parameter. The corresponding classical field theory allows for the stabilization of Skyrmionic localized states and extended textures [3]. The notion of a glassy structure as an entangled network of defect lines is replaced by the complex geometry of an elastic and frustrated continuum that can display both “rotation” or twisting and suppression of the ideal local order. The Skyrmions in the simplest version of the frustration models are close, but soft relatives of the hedgehog solutions in Skyrme’s original SU(2) symmetric model for nucleons. It is argued that stable Skyrmions are formed at elevated temperatures in molecular liquids and that their condensation into frustrated textures underlies the stability of supercooled and glassy states. — [1] U.K.Rößler, A.N.Bogdanov, C.Pfleiderer, Nature (London) 442, 797 (2007). [2] S. Sachdev, D.R. Nelson, Phys. Rev. B 32 (1985) 1480. [3] U.K.Rößler, A.N.Bogdanov, J.Non-Cryst.Solids 354, 4198 (2008).