Depletion of two-level systems in highly stable glasses with different molecular ordering

Manuel Moratalla Martín, Marta Rodríguez López, Cristian Rodríguez Tinoco, Javier Rodríguez-Viejo, Rafael J. Jiménez Riobóo, Miguel Ángel Ramos

Research output: Contribution to journalArticleResearchpeer-review


Recent findings of structural glasses with extremely high kinetic and thermodynamic stability have attracted much attention. The question has been raised as to whether the well-known, low-temperature "glassy anomalies" (attributed to the presence of two-level systems [TLS] and the "boson peak") persist or not in these ultrastable glasses of much lower configurational entropy. To resolve previous contradictory results, we study a particular type of ultrastable glass, TPD, which can be prepared by physical vapor deposition in a highly-stable state with different degrees of layering and molecular orientation, and also as a conventional glass and in crystalline state. After a thorough characterization of the different samples prepared, we have measured their specific heat down to 0.4 K. Whereas the conventional glass exhibits the typical glassy behaviour and the crystal the expected Debye cubic dependence at very low temperatures, a strong depletion of the TLS contribution is found in both kinds of ultrastable glass, regardless of their layering and molecular ordering.
Original languageEnglish
JournalCommunications Physics
Publication statusPublished - 2023


  • Boson peaks
  • Configurational entropy
  • Highly stables
  • Kinetics and thermodynamics
  • Lows-temperatures
  • Molecular ordering
  • Physical vapour deposition
  • Stable state
  • Structural glass
  • Two-level system


Dive into the research topics of 'Depletion of two-level systems in highly stable glasses with different molecular ordering'. Together they form a unique fingerprint.

Cite this