LISE 303 12pm – 1pm April 11th 2025

Abstract: Engineering arbitrary surface acoustic wave (SAW) band structures within piezoelectric materials such as LiNbO3 can significantly advance classical telecommunications and quantum information processing. Through the deposition of a periodic array of metallic microstructures on LiNbO3, we can control the speed of sound or gap out SAW dispersion completely. Quantifying such control over the band structure requires direct visualization of traveling SAWs, which was mostly limited to micronscale spatial resolution or narrow frequency ranges. Here, we introduce electrostatic force microscopy (EFM) as a novel detection method for the direct visualization of travelling SAWs in honeycomb metamaterials on LiNbO3. This method achieves sub-micron resolution and broad bandwidth measurements, enabling us to map the complete band structure of a SAW graphene analog, including a Dirac cone at the K point and a band gap when sub-lattice symmetry is broken. This technique facilitates faster and more detailed studies of complex SAW metamaterials, establishing a platform for the arbitrary control over SAW dispersions.
About the speaker: Ben obtained a BA in physics and a BS in molecular engineering from the University of Chicago in 2018. He is receiving his PhD in condensed matter physics in May 2025 from Harvard University. He focused on the exploration of 2D materials via two distinct pathways: 1) the design and construction of a novel mK-base temperature scanning probe microscope to perform topologically protected quantum computation in topological superconductors, and 2) the development of classical acoustic metamaterials platforms for applications ranging from microwave technologies to simulating quantum systems. His expertise includes custom and commercial numerical modeling software, nanofabrication, vacuum and cryogenic technologies, and ultra-cold system design. He is currently seeking research positions in academia or industry to continue his scientific research journey.