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

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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?

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• 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