Professor Xavier Roy

Professor Xavier Roy
Department of Chemistry
Columbia University
Abstract

Next level quantum materials

Over the past 15 years, two-dimensional (2D) materials have garnered significant attention due to their exceptional physical, mechanical, and chemical properties, as well as our ability to seamlessly incorporate them into various devices. In this seminar, I will present our recent advancements in the development of the next generation of 2D materials. To begin, I will discuss our efforts to assemble atomically defined clusters of atoms, which we refer to as “superatoms,” into hierarchical 2D structures. These superatoms mimic the role of atoms in conventional 2D “atomic” solids, resulting in remarkable material properties. I will highlight recent synthetic breakthroughs and explore the distinctive transport behaviors that emerge due to the atomic precision of the 2D lattice and the specific interactions between these building blocks. In the second part of the presentation, I will introduce novel atomic 2D materials that have been developed in our laboratories in recent years. Specifically, I will delve into how magnetic order strongly influences optical transitions in the 2D magnetic semiconductor CrSBr. Additionally, I will provide insights into the synthesis and characterization of CeSiI, the first f-electron-based heavy fermion metal, which also falls under the category of 2D van der Waals (vdW) materials. Conceptually, our synthetic design takes a traditional 3D intermetallic heavy fermion compound and slices it into atomically thin vdW sheets by incorporating iodine into the structure. The resulting material is cleavable and effectively 2D electronically, even in bulk crystals.

Xavier Roy

Professor Xavier Roy received a B.Eng. (2002) and a Master of Applied Science (2005) in Chemical Engineering from Ecole Polytechnique of Montreal, performing research under the guidance of Prof. Basil Favis. He earned his Ph.D. in Chemistry with Prof. Mark MacLachlan at the University of British Columbia in 2011, working as an NSERC Alexander Graham Bell Scholar. He went on to do postdoctoral research as a Canada NSERC Postdoctoral Fellow with Prof. Colin Nuckolls at Columbia University from 2011 to 2013. He joined the Columbia University Faculty in 2013 as an Assistant Professor of Chemistry, and was promoted in 2018 to the rank of Associate Professor and received tenure in 2020.

Hosted by Professor Gwendolyn Bailey