Abstract
dc:descriptionThe quantum excitations in glasses have long presented a set of puzzles for condensed matter scientists. A common view is that they are largely disordered analogs of elementary excitations in crystals, supplemented by two level systems which are chemically local entities coming from disorder. This thesis suggests a radical revision of this picture. We argue that the excitations in low temperature glasses are deeply connected to the energy landscape of the glass when it vitrifies: the excitations are not low excited states built on a single ground state but locally defined resonances, high in the energy spectrum of a solid. Two level systems involve resonant collective tunneling motions of around two hundred molecular units. The Boson Peak and the plateau in thermal conductuvity, observed at higher temperatures, arise from the same motions but the motions are no longer fully coherent.
Degree
thesis:*- Name thesis:degree_name
- Ph.D.
- Level thesis:degree_level
- Dissertation
- Discipline thesis:degree_discipline
- Chemistry
- Grantor
- University of Illinois at Urbana-Champaign
- Year dc:date
- 2015
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Lubchenko, Vassiliy
- Contributors dc:contributor
-
- Wolynes, Peter G.
Subjects
dc:subject × 1Rights
- Language dc:language
- eng
Identifiers
dc:identifier.*- Identifier
- (MiAaPQ)AAI3070376
- OAI identifier oai:identifier
- oai:www.ideals.illinois.edu:2142/84085