<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:times new roman,new york,times,serif;font-size:12pt"><b><span style="font-weight: bold;">From:</span></b> xirainbow <nkxirainbow@gmail.com><br><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;"><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;"><font face="Tahoma" size="2"><b><span style="font-weight: bold;"></span></b></font><br>> Is there LO-TO splitting far away from Gamma point?<br><br>No.<br><div><br>>How large is the influence range of LO-TO splitting in Brillouin zone? One hundred percent?</div><div><br>It depends on the macroscopic dielectric constant and Born effective charge, see any good solid state physics textbook <br>or review paper Rev.Mod.Phys. 73, 515 (2001). <br>It is clear that the effect is more pronounced for (polar) insulators (large band gap).
<br></div><div><br>Bests,<br>Eyvaz.<br><div><br clear="all">
-------------------------------------------------------------------<br>Prof. Eyvaz Isaev, <br>Department of Physics, Chemistry, and Biology (IFM), Linkoping University, Sweden <br>Theoretical Physics Department, Moscow State Institute of Steel & Alloys, Russia, <br>isaev@ifm.liu.se, eyvaz_isaev@yahoo.com
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