Moire Materials as laboratories for quantum embedding theories*

Quantum embedding theories such as dynamical mean field theory approximate the full quantum dynamics and thermodynamics of an interacting electron system in terms of the properties of a ``quantum impurity model” (few degree of freedom quantum system coupled to non or weakly-interacting bath). The downfolding of the full interacting system to the impurity model, and the adequacy of the quantum impurity model are important open issues in the theory of correlated quantum materials. ``Moire” materials comprised of two or more atomically thin sheets with a lattice constant mismatch or a relative twist angle have emerged as an important experimental platform for the investigation of correlated electron physics, due to the exceptional tunability of unit cell size and symmetry, electron concentration, interaction strength and other properties and to the ability to access parameter regimes inaccessible in conventional solids.   This talk will summarize recent applications of embedding theories to experiments on Moire materials, including tests of the dynamical mean field picture of the metal insulator transition in the presence of Zeeman and orbital coupling to magnetic fields, the theory of transport near van Hove singularities and at high temperatures, and orbital-selective Mott and heavy fermion physics.

This work is based on collaborations with Jiawei Zang, Jennifer Cano, Antoine Georges, Armelle Celarier, Chris Marianetti, Zhengqian Cheng, Daniele Guerci, Valentin Crepel, Thomas Schaefer and Marcel Klett.