English

Two-Level Systems and the Tunneling Model: A Critical View

Disordered Systems and Neural Networks 2021-01-11 v1 Soft Condensed Matter

Abstract

The thermal and acoustic properties displayed by a wide variety of glasses at low temperatures are well described by the model of tunneling two level systems (TLS). We review the standard TLS model as well as developments that have occurred since the earlier work. In spite of half a century of effort and impressive successes, mysteries still remain. We discuss some of these longstanding puzzles about glasses at low temperatures and speculate about future directions.

Keywords

Cite

@article{arxiv.2101.02787,
  title  = {Two-Level Systems and the Tunneling Model: A Critical View},
  author = {Clare C. Yu and Hervé M. Carruzzo},
  journal= {arXiv preprint arXiv:2101.02787},
  year   = {2021}
}

Comments

28 pages, 1 figure, 1 table. To be published as Chapter 5 of the book entitled, "Low-Temperature Thermal and Vibrational Properties of Disordered Solids: A Half-Century of Universal "Anomalies" in Glasses," edited by M. A. Ramos, World Scientific Press

R2 v1 2026-06-23T21:54:01.594Z