2005/06/28 by Vassiliy Lubchenko, Vassiliy Lubchenko§, Robert J. Silbey +1
Materials Science · Physics and Astronomy · #Material Dynamics and Properties #Quantum Electrodynamics and Casimir Effect #Quantum optics and atomic interactions #cond-mat.dis-nn #cond-mat.mtrl-sci
paper · pdf · doi:10.1080/00268970500395661
Submitted for publication; April 27, 2005 version
arxiv created 2005/06/28 · openalex publication_date 2006/04/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/29
Amorphous solids exhibit intrinsic, local structural transitions, which give rise to the well-known quantum-mechanical two-level systems at low temperatures. We explain the microscopic origin of the electric dipole moment of these two-level systems: the dipole emerges as a result of polarization fluctuations between near degenerate local configurations, which have nearly frozen in at the glass transition. An estimate of the dipole's magnitude, based on the random first-order transition theory, is obtained and is found to be consistent with experiment. The interaction between the dipoles is estimated and is shown to contribute significantly to the Grüneisen parameter anomaly in low T glasses. In completely amorphous media, the dipole moments are expected to be modest in size despite their collective origin. In partially crystalline materials, however, very large dipoles may arise, possibly explaining the findings of Bauer and Kador [J. Chem. Phys., 118, 9069 (2003)].