Laboratoire de Physique Théorique
Toulouse - UMR 5152

Diffusion is the transport regime most commonly encountered in nature and yet, we do not have to this day a full comprehension of the microscopic origins of diffusion. In order to make progress, it is thus important to have at our disposal toy models that showcase the right physical behavior while remaining simple enough to allow analytical computations.

I will present a class of models called quantum stochastic Hamiltonians (QSH) that meet these criteria. Using Keldysh formalism, I will first show how to exactly compute their Green’s function. Relying on this exact solution, I will present a generic perturbative formalism allowing to derive the current at the diffusive scale with minimal computational effort. Applications to the dephasing model, QSSEP and long-range stochastic hopping model will be presented.