Laboratoire de Physique Théorique

de la Matière Condensée

Riccardo Rossi (Flatiron Institute, New-York)
New diagrammatic Monte Carlo approches to the quantum many-body problem

Finding a way to numerically simulate many interacting quantum particles would be of great fundamental and practical value. In this talk, I will discuss a broad class of approaches based on diagrammatic expansions that allows to obtain numerically-exact results in a time polynomially increasing with the inverse of the requested precision. Recent advances allow to include renormalization and non-perturbative information (e.g. Dynamical Mean Field Theory for lattice problems) in the expansion using a succinct, and, most importantly, very efficient, formalism. I will present state-of-the-art numerically-exact results for the doped square-lattice Hubbard model, and the generic efficient code we have developed.