Vanishing soft mode in phonon spectrum of ladder lattice
Ferroelectrics : the international journal devoted to the theoritical, experimental, and applied aspects of ferroelectrics and related materials Volume 414
Page 48-54
published_at 2011
Title
Vanishing soft mode in phonon spectrum of ladder lattice
Creator Keywords
soft phonon
optical and acoustic branches
anticrossing
dispersion relation
phonon spectrum
ferroelectric transition
A ladder lattice model is studied analytically to understand the coupling between the acoustic and optical phonons. When the optical phonon becomes soft at a G-point, the anticrossing between the two branches takes place. In a simple case, the optical spectral intensity vanishes around the anticrossing wave number. The coupled spectral function is not a simple superposition of two damped harmonic forms. It is shown that the off-diagonal component of static susceptibility for the elastic and polar waves is decisive to obtain the correct spectral intensity.
Languages
eng
Resource Type
journal article
Publishers
Gordon and Breach Science Pub
Date Issued
2011
File Version
Author’s Original
Access Rights
open access
Relations
[ISSN]0015-0193
[NCID]AA00644949
[isVersionOf]
[URI]http://www.tandfonline.com/loi/gfer20
Schools
大学院理工学研究科（理学）