"From 3D to 2D and back again"

Mon, 10/08/2018 - 4:15pm
428 Pupin Hall
Cory Dean
Columbia University

"From 3D to 2D and back again"

Graphene , a single layer of carbon atoms arranged in a hexagonal lattice, is probably the best known, and most extensively characterized two-dimensional material.  However, this represents just one of a larger class of layered materials, in which weak interlayer-forces make it possible to mechanically isolate monolayers from the bulk.  This weak interlayer bonding also makes it possible to interleave monolayers from different crystals together to form entirely new layered structures.  Fabricating materials by the mechanical assembly of individual layers provides a new and unprecedented level of control in device engineering where crystals with wildly different properties can be mixed and match, virtually at will.  In this talk I will describe some of the techniques we have developed to make this possible and highlight new quantum phases that emerge as a result. I will additionally discuss recent efforts where,  by tuning the geometry of  these heterostructures at the nanoscale,  we realize the capability to induce and dynamically control novel electronic phases in these systems, in ways that are not possible in conventional materials. 

About the speaker

Cory Dean's research focuses on both fundamental studies, and technological applications of solid state devices at the meso- and nano-scale. General areas of study include electron transport in degenerate many body systems where strong interactions lead to new states of matter and novel electronic behaviour resulting from new device archictectures. Systems that we study include layered materials such as graphene and related heterostructures, transition metal dichalcogenides, and topological insulators as well as more conventional 2D electron systems such as III-V semiconductors. Cory's research group probes these systems by combining transport studies with a variety of experimental knobs such as applied magnetic and electrostatic fields, variable tempeartures from ambient down to miliKelvin, high vacuum, spatial confinement down to the nano-scale, variable charge carrier densities, and unconventional NMR techniques.

More details can be found here.