Starts 23 Feb 2016 14:00
Ends 23 Feb 2016 16:00
Central European Time
Abstract: The study of many-body quantum eigenstates has recently revealed a novel dynamical transition, dubbed many-body localization, intimately related to the mechanism of quantum thermalization and resulting from the competition between disorder and interaction. When the disorder becomes sufficiently strong, ergodicity is not ensured and standard thermodynamics does not apply. Here, we show manifestations of the weak/strong disorder regime in an open and driven quantum system. We consider 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 that at moderate disorder, nuclear spins equilibrate to the eff ective spin-temperature established among the electron spins of radicals, as expected from the quantum theory of thermalization. Interestingly, the highest polarization is reached at a point where the establishment of a spin temperature is just about to break down due to the incipient many-body localization transition in the electron spin system.