Speaker: Pierre Deymier, MSE
Title: Topological Acoustics
Abstract:
The unconventional, recently emerged notion of topology is an additional degree of freedom in the control, analysis, and applications of sound waves. Specifically, one class of topological acoustics systems exploits the geometric amplitude and phase characteristics of a wave imparted by symmetry breaking. Nontrivial topologies for acoustic waves lead to extraordinary properties such as nonreciprocity and behaviors analogous to those of quantum systems or condensed matter. Symmetry breaking by intrinsic or extrinsic origins leads to quantization through topological invariance of the wave function and are akin to electronic and photonic topological insulators. Another class of topological acoustic systems exhibit emergent symmetry breaking of wave functions to create hidden topological order that compare to quantum magnetic systems such as string order in strongly correlated spin chains. While topological insulator-like acoustic systems essentially associate with linear band structure characteristics, topological order systems also result from strong correlations and nonlinearity.