Phonon focusing patterns in cubic crystals
Litian WangØstfold University College
Fall 2007
Waves in condensed matters
• Crystalline Solids:– Logitudinal waves– Transverse waves (SH,SV)
Waves in condensed matters• Crystalline Solids:
– Logitudinal waves– Transverse waves (SH,SV)
Anisotropy
– Logitudinal waves (L)– Transverse waves (FT) – Slow transverse waves– Transverse waves (ST) – Fast transverse waves
Phonon focusing
?
?
The problema) Given elastic constants, can we determine
the dimension of the patterns analytically?b) Given a focusing pattern, can we determine
the elastic constants?
?
?
• Phonon focusing patterns in cubic crystals• Theoretical analysis• Numerical demonstration
Conclusion
Conclusionsa) Given elastic constants, can we determine
the dimension of the patterns analytically?Yes, with analytical result
a) Given a focusing pattern, can we determine the elastic constants?Yes, with analytical accuracy.
2 x 26.44o
2 x 19.64o
