Lars Schonenberg

Research

I study systems of ultracold atoms. In particular, I am interested in the regime of strong interactions where analytic methods usually fall short, but where one can nevertheless use numerical approaches to extract meaningful results. These numerical techniques include fixed node difussions Monte Carlo, of which we use the casino implementation. I am also interested in the development of a novel Monte Carlo approach using a configurion space of Feynman diagrams as opposed to particles, appropriately named diagrammatic Monte Carlo (diag-MC).

A major challenge when numerically simulating strongly-interacting systems is to come up with a description for the interaction potential that accurately captures the relevant physics, yet is easy to handle numerically. We have therefore developed the Ultra Transferable Pseudopotential (UTP). With this UTP we accurately describe the interactions of cold Fermi-gasses, while at the same time its smooth form delivers many numerical advantages.