Recently, many-body localization (MBL) has emerged as a possible way to avoid quantum thermalization when disorder is sufficiently strong to compete with interaction. In this situation, ergodicity is not ensured and standard thermodynamics does not apply. par We show manifestations of the weak/strong disorder regime in an open and driven quantum system. In particular, we focus on a minimal model for Dynamic Nuclear Polarization (DNP), the most effective technique in NMR to increase nuclear polarization by doping a compound with unpaired electrons. We show two distinct dynamical phases separated by the MBL transition where the hyperpolarization becomes optimal. Finally, we present a similar procedure for the Anderson 3D tight-binding model and again we confirm that maximal efficiency coincides with the known localization transition for this model.

Rudolf Peierls Centre for Theoretical Physics, University of Oxford