Novel 2D materials and devices

Ever since the isolation of single-atom-thick graphene an ever-growing number of two-dimensional (2D) atomic crystals have been created. These 2D atomic crystals have properties that are very different from their 3D bulk crystals, as 2D atomic crystals are comprised of stacks of such layers, and offer unique opportunities for advances in creating new quantum phases, new electronic devices, energy harvesting, catalysis, and nanomechanics. Integrating these 2D crystals into a gated structure offers a way to control their carrier density, which can strongly influence formation of various electronic group states. Their crystalline nature also lends themselves as a platform for high resolution scanning probe techniques. Our group is exploring the opportunities such 2D materials are providing in a number of directions, from graphene to their twisted stacks and to other 2D transition metal dichalcogenides (TMDs). Our STM work on twisted bilayer graphene devices has already provided considerable new insights into the novel properties of that system (MATBG). Similar to that effort, we have ongoing experiments in exploring correlated and topological properties of twisted double bilayers of graphene (X. Li et al. 2020). In other efforts, in collaboration with Prof. Sanfeng Wu's group, we are also examining the properties of monolayer WTe2, which shows novel properties and signatures of been an exitonic insulator (Y. Jia et al. 2020). We are exploring these 2D materials and devices as a novel platform for creating new topological and correlated electronic states, and will be exploring them with a variety of scanning probe techniques.