The crystals themselves are constructed from lead balls 1 cm in diameter,
coated with a 2.5-mm layer of silicone rubber, and placed inside an epoxy matrix.
The strong periodic variation in density creates spectral gaps that prevent
the transmission of waves. This is analogous to the attenuation of
electromagnetic waves in photonic crystals. Liu's team placed a sound source near
the crystal and compared the amplitudes of sound waves at the surface of the crystal
and at the centre of the crystal. They found distinct gaps in the range of
frequencies transmitted through the crystal.
The missing frequencies are absorbed by certain oscillations of the coated spheres,
which are like vibrations in molecular crystals.
The crystals themselves are constructed from lead balls 1 cm in diameter,
coated with a 2.5-mm layer of silicone rubber, and placed inside an epoxy matrix.
The strong periodic variation in density creates spectral gaps that prevent
the transmission of waves. This is analogous to the attenuation of
electromagnetic waves in photonic crystals. Liu's team placed a sound source near
the crystal and compared the amplitudes of sound waves at the surface of the crystal
and at the centre of the crystal. They found distinct gaps in the range of
frequencies transmitted through the crystal.
The missing frequencies are absorbed by certain oscillations of the coated spheres,
which are like vibrations in molecular crystals.
The crystals themselves are constructed from lead balls 1 cm in diameter,
coated with a 2.5-mm layer of silicone rubber, and placed inside an epoxy matrix.
The strong periodic variation in density creates spectral gaps that prevent
the transmission of waves. This is analogous to the attenuation of
electromagnetic waves in photonic crystals. Liu's team placed a sound source near
the crystal and compared the amplitudes of sound waves at the surface of the crystal
and at the centre of the crystal. They found distinct gaps in the range of
frequencies transmitted through the crystal.
The missing frequencies are absorbed by certain oscillations of the coated spheres,
which are like vibrations in molecular crystals.
The crystals themselves are constructed from lead balls 1 cm in diameter,
coated with a 2.5-mm layer of silicone rubber, and placed inside an epoxy matrix.
The strong periodic variation in density creates spectral gaps that prevent
the transmission of waves. This is analogous to the attenuation of
electromagnetic waves in photonic crystals. Liu's team placed a sound source near
the crystal and compared the amplitudes of sound waves at the surface of the crystal
and at the centre of the crystal. They found distinct gaps in the range of
frequencies transmitted through the crystal.
The missing frequencies are absorbed by certain oscillations of the coated spheres,
which are like vibrations in molecular crystals.
The crystals themselves are constructed from lead balls 1 cm in diameter,
coated with a 2.5-mm layer of silicone rubber, and placed inside an epoxy matrix.
The strong periodic variation in density creates spectral gaps that prevent
the transmission of waves. This is analogous to the attenuation of
electromagnetic waves in photonic crystals. Liu's team placed a sound source near
the crystal and compared the amplitudes of sound waves at the surface of the crystal
and at the centre of the crystal. They found distinct gaps in the range of
frequencies transmitted through the crystal.
The missing frequencies are absorbed by certain oscillations of the coated spheres,
which are like vibrations in molecular crystals.
