Tuesday, 15 October 2024 at Noon | 490 Cory Hall
Watch the seminar recording here.
Professor Yuan Cao
Electrical Engineering and Computer Sciences | University of California, Berkeley
Host: Jon Candelaria
ABSTRACT
Two-dimensional materials (2DM) and their heterostructures offer tunable electrical and optical properties, primarily modifiable through electrostatic gating and twisting. While electrostatic gating is a well-established method for manipulating 2DM, achieving real-time control over interfacial properties remains a frontier in exploring 2DM physics and advanced quantum device technology. Current methods, often reliant on scanning microscopes, are limited their application scope, lacking the accessibility and scalability of electrostatic gating at the device level. In this work, we introduce an on-chip platform for 2DM with in situ adjustable interfacial properties, employing a microelectromechanical system (MEMS). This platform comprises compact and cost-effective devices capable of precise voltage-controlled manipulation of 2DM, including approaching, twisting, and pressurizing actions. We demonstrate this technology by creating synthetic topological singularities, such as half-skyrmions or merons, in the nonlinear optical susceptibility of twisted hexagonal boron nitride (h-BN). A key application of this technology is the development of integrated light sources with real-time and wide-range tunable polarization. Additionally, we envision a quantum analog capable of generating entangled photon pairs with adjustable entanglement properties. Our work extends the capabilities of existing technologies in manipulating low-dimensional quantum materials and paves the way for novel hybrid 2D-3D devices, with promising implications in condensed-matter physics, quantum optics, and related fields.
BIO
Yuan Cao is an Assistant Professor of Electrical Engineering and Computer Science starting July 2024. He obtained bachelor's degree at University of Science and Technology of China in 2014, and master's degree and Ph.D. at Massachusetts Institute of Technology in 2016 and 2020 respectively. From 2021 to 2024, he served as a Junior Fellow at Harvard University, before joining Berkeley as faculty.
His primary research interest is in the electrical, optical, and mechanical properties of low-dimensional materials, and how to engineer these properties and find applications for them using cross-disiplinary approaches including nanotechnology, metamaterials, and microelectricalmechanical systems (MEMS).
Cao received numerous award and prizes for his contribution in physics. In 2018, his research on superconductivity in twisted graphene was at the top of 'Nature's 10' list as well as the 'Physics Breakthrough of the Year'. He is subsequently awarded with 'TIME 100 Next for rising stars' in 2019, Sackler Prize in Physics in 2020, McMillan Award in 2021, and Richard L. Greene Dissertation Award in 2022.
Interested in nominating someone to speak at the BSAC Technology Seminar? We welcome you to submit a speaker nomination here