Quantum many-body dynamics and the quest for massive entanglement production

Tommaso Roscilde (ENS-Lyon)

Many-body quantum entanglement is the fundamental trait which separates our macroscopic world and the microscopic one, in which Schrödinger’s cats do exist — they are simply too small to meow, for the moment… Many-body entanglement is also the central resource of long-sought quantum technologies of next generation. Identifying effective ways to produce many-body entanglement over the largest possible scales, and in the shortest possible times, is clearly a grand challenge for quantum many-body theory and non-equilibrium quantum statistical mechanics.

In this talk I will discuss how turning to long-range interacting systems is a natural choice for effective entanglement production. The onset of large-scale multipartite entanglement corresponds in general to the relaxation of the system towards long-range order; and the latter is typically associated with thermalisation of closed quantum systems. I will show that this point of view, while valid in some cases — such as the quasi-adiabatic preparation of low-energy states — may not be appropriate for the most effective forms of entanglement dynamics. The latter defy the conventional classification schemes (ergodic vs. non-ergodic) of quantum dynamics, and suggest a more inclusive classification, which is already accepted in classical physics.

Contact : N. Laflorencie