title: Universal features of terahertz absorption in disordered materials.
abstract: Using an analytical theory, experimental terahertz time-domain spectroscopy data, and numerical evidence, we demonstrate that the frequency dependence of the absorption coupling coefficient between far-infrared photons and atomic vibrations in disordered materials has the universal functional form, C(omega)=A+Bomega(2), where the material-specific constants A and B are related to the distributions of fluctuating charges obeying global and local charge neutrality, respectively.
authors.affiliation: St. Catharine's College, Trumpington Street, Cambridge CB2 1RL, United Kingdom. snt1000@cam.ac.uk
authors.forename: S N
authors.initials: SN
authors.lastname: Taraskin
authors.forename: S I
authors.initials: SI
authors.lastname: Simdyankin
authors.forename: S R
authors.initials: SR
authors.lastname: Elliott
authors.forename: J R
authors.initials: JR
authors.lastname: Neilson
authors.forename: T
authors.initials: T
authors.lastname: Lo