Band tails in lattices of polar oscillators with short-range force constant disorder
M C Payne; M C Payne; Cavendish Lab., Cambridge Univ., UK
Журнал:
Journal of Physics C: Solid State Physics
Дата:
1986-04-20
Аннотация:
Investigates band-tail states in a system of polar oscillators that have disordered short-range force constants. In the absence of disorder, the frequencies of the transverse and longitudinal modes are separated by Lyddane-Sachs-Teller splitting. The states in the band tail appear to be formed as a result of large fluctuations in the short-range force constants on a small number of atoms. This contrasts with band-tail states in disordered electronic systems which arise because of negative fluctuations in the potential over a large number of atoms.
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