Acoustic Simulations of Quantum Materials
In the last few years there has been an explosion of new quantum materials, ranging from topology to “twistronics”. Topological materials may be engineered for applications from efficient switches to spin-based computing. “Twistronics” entails the construction of layered materials with emergent electronic and magnetic properties by stacking and twisting individual 2D materials such as graphene. Despite the vast possibilities waiting to be explored, the assembly of such microscopic devices with the necessary precision has proven laborious and expensive. Here we have developed a tangible acoustic analog to these tiny quantum structures! We show how sound waves propagating through millimeter-scale holes in a steel plate act exactly like electron waves propagating through nanometer-scale twisted bilayer graphene  . We show how to construct a topological logic gate for ultrasound . Our 3D-printed acoustic structures could offer a new way to intuitively understand and rapidly preview quantum materials and complex devices that exceed current computational and experimental capabilities.
 “Simulating twistronics in acoustic metamaterials” Gardezi et al, 2D Materials 8, 031002 (2021)
 “Topological phononic logic” Pirie et al, Phys. Rev. Lett. 128, 015501 (2022)
Funding: This work was supported by the National Science Foundation Science & Technology Center for Integrated Quantum Materials, Grant No. DMR-1231319.