Phys.org September 25, 2023 Pressure is encountered in various fields – atmospheric pressure in meteorology, blood pressure in medicine, etc. Examining the physical properties of materials under a wide range of thermodynamic states is a challenging problem due to the extreme conditions the material must experience. Such temperature and pressure regimes, which result in a change in the refractive index and sound velocity, can be accessed by optoacoustic interactions such as Brillouin–Mandelstam scattering. An international team of researchers (Germany, France, Australia) demonstrated the Brillouin–Mandelstam measurements of nanolitre volumes of liquids in extreme thermodynamic regimes enabled by a fully sealed liquid-core […]
Tag Archives: Sound wave
Breaking the symmetry of sound waves allows the sound to be directed to a certain place
Phys.org November 29, 2021 An international team of researchers (China, Spain) constructed a topological gallery insulator using sonic crystals made of thermoplastic rods that are decorated with carbon nanotube films, which act as a sonic gain medium by virtue of electro-thermoacoustic coupling. By engineering specific non-Hermiticity textures to the activated rods, they were able to break the chiral symmetry of the whispering-gallery modes, which enables the out-coupling of topological ‘audio lasing’ modes with the desired handedness. Adding gain makes it possible to amplify to break the chiral symmetry. The laboratory tests have demonstrated that when these elements are applied, the […]