Incommensurate systems as model compounds for disorder revealing low-temperature glasslike behavior

Gyorgy Remenyi (1) , S. Sahling (1, 2) , K. Biljaković (1, 3) , D. Starešinić (3) , Jean-Claude Lasjaunias (4) , José-Emilio Lorenzo (1) , Pierre Monceau (1) , Andres Cano (5, 6)

1 NEEL - MagSup - Magnétisme et Supraconductivité
2 TU Dresden - Technische Universität Dresden = Dresden University of Technology
3 Institute of Physics
4 NEEL - Cryo - Cryogénie
5 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
6 ESRF - European Synchrotron Radiation Facility

We show that the specific heat of incommensurately modulated crystals with broken translational periodicity presents similar features at low temperatures to those of amorphous and glass materials. Here we demonstrate that the excess to the constant Cp(T)/T3 law (or Debye limit) is made up of an upturn below 1 K and of a broad bump at T≈10  K that directly originates from the gapped phase and amplitude modes of the incommensurate structure. We argue that the low-energy dynamics of incommensurate systems constitute a plausible simplification of the landscape of interactions present in glasses, giving rise to their low-temperature anomalies.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Gyorgy Remenyi, S. Sahling, K. Biljaković, D. Starešinić, Jean-Claude Lasjaunias, et al.. Incommensurate systems as model compounds for disorder revealing low-temperature glasslike behavior. Physical Review Letters, 2015, 114 (19), pp.195502. ⟨10.1103/PhysRevLett.114.195502⟩. ⟨hal-01161560⟩