Universal features of terahertz absorption in disordered materials.
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.
Taraskin
S N
SN
St. Catharine's College, Trumpington Street, Cambridge CB2 1RL, United Kingdom. snt1000@cam.ac.uk
Simdyankin
S I
SI
Elliott
S R
SR
Neilson
J R
JR
Lo
T
T