Kenji Yasuda
Assistant Professor, Applied and Engineering Physics
Cornell University

Engineering Symmetry and Band Structures in Artificial Heterostructures

A dream of materials science is to physically synthesize compounds by arranging atoms one-by-one in arbitrary positions. This aspiration has been partially realized over the past decade, thanks to the advent of van der Waals heterostructures. atomically thin 2D materials can be stacked layer-by-layer to design artificial heterostructures, enabling the precise engineering of symmetry and band structures.
To illustrate the power of the physical assembly method, I will first explain how we can modify the symmetry of 2D materials by altering the stacking order. Taking the examples of boron nitride and transition metal dichalcogenides, I will demonstrate how modifying the stacking angle can induce ferroelectricity. I will especially focus on the recent findings regarding device performance as ferroelectric nonvolatile memory, showcasing atomically-thin, ultrafast, and high-endurance switching that surpasses conventional limitations thanks to the unique nature of ferroelectricity. Subsequently, I will elucidate how utilizing ferroelectric moiré superlattices, created by twisting the layers, introduces universal substrates for band structure engineering. Finally, I will discuss my plans to leverage these potentials in symmetry and band structure engineering to attain quantum materials by design at Cornell AEP.

About the speaker: Kenji Yasuda earned his Ph.D. in Applied Physics in 2018 from the University of Tokyo, where he discovered various spintronic functionalities in magnetic topological insulator thin films. He then moved to the Massachusetts Institute of Technology, where he pioneered the field of artificial ferroelectrics based on van der Waals heterostructures. He will join the School of Applied and Engineering Physics at Cornell as a visiting assistant professor in October 2023, and as an assistant professor in January 2024. The Yasuda lab aims to design quantum nanomaterials and heterostructures to explore novel physical properties and functionalities.

Hosted by Valla Fatemi

Pizza served starting at 12:10 p.m.
Please bring your own beverage