Two-level systems in glasses

A workshop at ENS Paris, November 25-27, 2019

Organisers: Camille Scalliet and Francesco Zamponi

  • Andrew Fefferman (Institut Néel, Grenoble)
  • Frances Hellman (UC Berkeley)
  • Wencheng Ji (EPFL, Lausanne)
  • Dmytro Khomenko (ENS Paris)
  • Francois Ladieu (IRAMIS-CEA Saclay)
  • Stefano Mossa (INAC-CEA Grenoble)
  • Miguel A. Ramos (Universidad Autónoma de Madrid)
  • David R. Reichman (Columbia University)
  • David Rodney (Université Lyon 1)
  • Camille Scalliet (Cambridge University)

Amorphous solids exhibit quasi-universal low-temperature thermal anomalies whose origin has been ascribed to a distribution of localized tunneling systems. Recent developments in experimental techniques enable the preparation of ultrastable glassy films. These new materials are as disordered as liquid cooled glasses, but do not present the supposedly "universal" low-temperature anomalies, suggesting that the density of two-level systems is reduced in stable glasses. These new experimental findings challenge the idea that disordered materials share universal anomalies. Numerical studies of two-level systems have been performed in the past to identify the microscopic nature of tunneling two-level systems. Recent algorithmic advances allow the synthesis of in silico glasses with quench rates ranging from those found in standard laboratory experiments to those found in ultrastable glasses prepared by vapor deposition. This advance opens new paths towards the characterization of two-level systems in computer glass, in an experimentally relevant temperature regime. The aim of this workshop is to bring together experimentalists and theoreticians to discuss these recent advances.

Workshop program (24 Rue Lhomond, Paris)
Monday 25 (Room L382-384)
13:45 Frances Hellman
15:15 Coffee break
15:45 David R. Reichman
17:15 Camille Scalliet
18:00 end
Tuesday 26 (Room L382-384)
9:30 Miguel A. Ramos
11:00 Coffee break
11:30 Wencheng Ji
12:15 Lunch break
14:30 David Rodney
16:00 Coffee break
16:30 Stefano Mossa
17:15 Andrew Fefferman
18:00 end
Wednesday 27 (Room Conf IV)
9:30 Francois Ladieu
11:00 Coffee break
11:30 Dmytro Khomenko
12:15 Lunch break
14:00 Round table and closing remarks
15:30 End of the workshop

Practical information:
There are no registration fees, however registration is mandatory, in order to organize the lunch. In order to register, please write an email entitled  "TLS Workshop" to Camille Scalliet (, indicating your name and affiliation. 

This workshop has received funding from the European Research Council (ERC) under the European Union's 
Horizon 2020 research and innovation programme (grant agreement n° 723955 - GlassUniversality).