Phase Diagram of Graphene from Lattice Field Theory

点击翻译按钮获取中文摘要

This project exploits analogies between the electronic properties of graphene and strongly coupled quantum field theories, most importantly quantum chromodynamics (QCD), to address some of the outstanding questions in relation to many-body strong-coupling effects which can nowadays increasingly well be studied experimentally in high quality samples of graphene. Ab-initio Monte-Carlo simulations based on our state-of-the-art tools from lattice field theory are used tosystematically explore the phase structure of graphene in the presence of external influences which favor various ordered phases. Dyson-Schwinger equations on the graphene lattice complement these ab-initio calculations, e.g., for pseudo-conformal behavior in very large volumes or finite charge-carrier densities where there is a fermion-sign problem as in QCD at finite baryon density. In particular, the project aims to determine which of the various Mott insulating phases occur inthe various regions of tunable parameters and whether they can be realized experimentally. It thereby addresses magnetic fields and magnetic catalysis as also relevant in heavy-ion collisions, defects as catalysts for pre-condensation and their analogies with instantons, the finite-density Lifshitz transition, and the relation between Anderson localization and chiral symmetry breaking as in hot QCD. The goal is to identify how graphene can best be used to test such non-perturbative quantum field theory concepts as also relevant for studies of the QCD phase diagram under well controllable experimental conditions.