Journal
PHYSICAL REVIEW B
Volume 84, Issue 22, Pages -Publisher
AMER PHYSICAL SOC
DOI: 10.1103/PhysRevB.84.224113
Keywords
-
Funding
- Research Grants Council of Hong Kong [600311]
Ask authors/readers for more resources
We show that two-dimensional phononic crystals exhibit Dirac cone dispersion at (k) over right arrow = 0 by exploiting dipole and quadrupole accidental degeneracy. While the equifrequency surface of Dirac cone modes is almost isotropic, such systems exhibit super-anisotropy, meaning that only transverse waves are allowed along certain directions, while only longitudinal waves are allowed along some other directions. Only one mode, not two, is allowed near the Dirac point, and only two effective parameters, not four, are needed to describe the dispersion. Effective medium theory finds that the phononic crystals have effectively zero mass density and zero 1/C(44)(eff) at the Dirac point. Numerical simulations are used to demonstrate the unusual elastic wave properties near the Dirac point frequency.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available