Abstract: In this talk I will discuss some non-Hermitian effects for wave propagation in phononics crystals and metamaterials. Such effects naturally emerge when the composite is made of gain-loss (non-conservative) media as in the case of PT symmetric unit cells. However, they can also emerge in perfectly conservative systems that I will discuss. These effects include anomalous scattering and enhanced sensitivity to wave sources, both of which could be used in sensing applications. The effect can also be used to sort the eigenvalues of any operator (including the phononic bandstructure) with higher computational efficiency than competing approaches — something that could be put to use in such areas as the calculation of thermal properties of phononic crystals.

Bio: Ankit Srivastava earned his M.S. and Ph.D. in structural engineering from the University of California, San Diego, after earning his B.Tech. in civil engineering from the Indian Institute of Technology, Guwahati. His research spans fundamental aspects of wave propagation in heterogeneous media, inverse material design for wave control, micromechanics and homogenization theory, and data-driven mechanics based on deep learning algorithms. The application areas of the research include cloaking, shockwave mitigation, transducer design, vibration control, energy-flow control, NDE and SHM, and virtual sensors. In recent years, he has made substantial contributions related to phononic eigenvalue problems and phononic metamaterials.