Capturing <i>In Operando</i> Electronic Structure of Microscopic 2D Materials

Angle Resolved Photoemission Spectroscopy (ARPES) is a premier technique for determining the electronic structure of correlated and topological materials. Recently, we and several other groups have adapted ARPES to submicron dimensions through the development of nano-scale scanning X-ray beams, creating so-called nanoARPES endstations at synchrotrons around the world. This exciting technique now enables the in operando measurement of electronic structure for materials in applied fields and currents, as well as the ability to probe the effect of screening and strain on many body physics in confined geometries . In this talk, I will present recent results in which nanoARPES is applied to 2D materials and heterostructures at length scales below 200 nm. These include few layer graphene and transition metal dichalcogenide / graphene heterostructures. Work done in collaboration with Professors T. Heinz (Stanford U.), J. Katoch (CMU), S Ulstrup, J. Miwa, and Ph. Hofmann (Aarhus U.).