Please note time and room change for this week only!
Understanding the properties of quantum matter remains one of the great challenges in physics and chemistry. Computation has an integral role to play in tackling this challenge. I will give an introduction to the fundamental issues facing accurate and predictive computations of quantum systems. I will then describe recent progress in combining field-theory and Monte Carlo simulations for computations in many-fermion systems. This framework can be used to simulate either a fully materials-specific Hamiltonian or a Hubbard-like model --- or indeed any electronic Hamiltonian in between as the former is ``down-folded'' to the latter. As an example of materials-specific calculations, results will be presented on the binding and magnetic properties of Cobalt adatom on graphene, a setup that has drawn interest for possible spintronics applications. As an example of model studies, we determine the nature of magnetic and charge correlations in the repulsive Hubbard model under doping. Its implications on the search for so-called FFLO phases with ultracold atoms will be discussed.