(Invited) Correlation in 2D Materials: Proximity Effects and Reactivity through the Lens of Quantum Monte Carlo

Abstract

2D materials are an exciting new class of materials promising for a wide range of engineering applications because of their exceptionally tunable electronic properties; indeed, these materials’ band gaps, charge densities, and spin densities can be dramatically altered just by stretching, compressing, or stacking them. Despite their promise, however, our modern understanding of 2D materials is partially obscured by the fact that most have only been computationally modeled using Density Functional Theory (DFT), a theory that cannot readily describe electron correlation and is known to yield widely varying results for such integral quantities as band gaps and molecular binding energies depending upon the exchange-correlation functional employed. In this talk, I will describe our recent efforts to model an array of 2D materials using fully correlated quantum Monte Carlo (QMC) techniques and the unanticipated physics these efforts have revealed. First, we will discuss for which materials our simulations reveal the largest discrepancies between DFT and QMC. We will then illustrate the importance of using correlated methods in the modeling of proximity-induced magnetism and spin-orbit coupling in multilayer materials. Lastly, if time permits, we will detail how correlation influences carbon dioxide reduction on post-transition metal chalcogenides. Altogether, this work paints a more complete picture of the electronic structure of this increasingly important class of materials.