NewFoS team is pursuing research at the frontiers of sound knowledge focused on the scientific principles of symmetry breaking and interactions through the four paradigm-changing notions of sound topology, duality, coherence and wave mixing.
From a historical perspective, our scientific understanding of sound dates back to Sir Isaac Newton's Principia, which examined its first mathematical theory. The mid-19th century book The Theory of Sound by Lord Rayleigh still constitutes the foundation of our modern theory of vibrations, whereas the quantum theory of phonons followed in the early part of the 20th century . During this nearly 300-year period, our understanding of sound waves has been nourished essentially by the paradigm of the plane wave and its periodic counterpart (the Bloch wave) in periodic media. This paradigm relies on the four canonical characteristics of waves: frequency (ω); wave vector (k); amplitude (A); and phase (ϕ). Over the past two decades, the fields of phononics and acoustic metamaterials have developed in which researchers manipulate the spectral and refractive properties of phonons and sound waves through their host material by exploiting ω and k. NewFoS research activities champion a new science of sound by pushing the frontiers of sound beyond considering only the domains of spectral and refractive properties. Indeed, it is in the canonical characteristic realms of A and ϕ where:
- Non-conventional new forms of sound reside;
- Remarkable sound-based quantum-like behavior exists;
- Radical nonlinear phenomena occur and coherence can be harnessed; and
- Exquisite wave mixing emerges. This new science of sound will open gateways to non-conventional forms of sound wave- or phonon-supporting media and new, technologically impactful forms of sound.