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View Full Version : A question about transverse/longitudinal acoustic/optical modes


gomboc
Oct26-11, 09:19 AM
I have a question I just started wondering about, and I'm not sure of the answer.

After looking at several phonon dispersion curves for crystals, it seems that most of the time, transverse optical modes have higher frequencies than longitudinal optical modes.

I'm curious as to why this is - it's kind of counter-intuitive, seeing as for acoustic modes, it's nearly always the longitudinal modes with the higher frequencies (which makes sense).

Any ideas?