Professor Erik Henriksen
Department of Physics
Washington University in St. Louis
Host: Kaul
Title: a-RuCl3 as a 2d crystalline acceptor: modulation doping, pn junctions, and the pursuit of Veselago's lens
Abstract: a-RuCl3 is a layered antiferromagnetic Mott insulator widely thought to host a quantum spin liquid state related to the Kitaev QSL. It can be exfoliated down to monolayer thicknesses and incorporated into van der Waals heterostructures along with graphene and myriad other atomically thin materials. Proximity of a-RuCl3 to graphene leads to a significant charge transfer between the two that, surprisingly, persists even when a thin insulating layer is inserted between them, a phenomenon analogous to modulation doping in epitaxially-grown semiconductors. In addition to constituting a new method of charge control in van der Waals stacks, we are using this to generate near-atomically-sharp pn junctions in graphene that may enable a realization of the electron-optic version of Veselago's lens.