Discipline: Technology and Engineering
Subcategory: Materials Science
Session: 2
Room: Virginia C
Gabrielle Lambert-Milak - University of Arizona
Co-Author(s): Neale Smith, University of Arizona, Tucson, AZ; Richie Curradi, University of Arizona, Tucson, AZ; and Anuja Oke, University of Arizona, Tucson, AZ; Pierre A. Deymier, University of Arizona, Tucson AZ; Pierre Lucas, University of Arizona, Tucson AZ; and N. Boechler, University of California, San Diego, La Jolla, CA
Non-backscattering, unidirectional propagation of elastic waves in solid state media can be achieved by subjecting materials to symmetry-breaking spatiotemporal modulation of their stiffness. The change in elastic properties can be photo-induced in chalcogenide materials, such as GeSe4 and Ge2Sb2Te5 (GST), which can undergo a change (thermo- , photo-elastic and phase change) in elastic stiffness upon irradiation by light. A dynamical modulation can be activated by a dynamically phase-modulated laser interference pattern. This photo-induced spatiotemporal modulation in chalcogenide materials was modeled using the COMSOL Multiphysics® software package. The model suggests the desired spatiotemporal modulation in elastic stiffness is achievable in both GST and GeSe4. In GST, rapid, reversible phase changes were simulated with a cooling rate of more than 1 K/ns, which is a requirement for the liquid-to-amorphous phase change to occur. In GeSe4, simulations show an induced change in elastic stiffness on the order of 0.2 GPa. The model demonstrates that chalcogenide materials offer a viable approach to realizing spatiotemporal elastic modulation in solid state media. The research was conducted at UC San Diego. In addition to gaining knowledge of acoustics, materials science, and modeling and simulation techniques, our team has developed confidence conducting research and realizing a project to completion. We have also developed leadership and communication skills through teamwork and collaboration with fellow engineers.
Funder Acknowledgement(s): Sponsor: NSF EFRI: NewLAW grant # 1640860
Faculty Advisor: Nicholas Boechler, nboechler@ucsd.edu
Role: Equally contributed to the team effort to develop and analyze the thermodynamic model.