QUROPE Quantum Information Processing and Communication in Europe

We extend the concept of superadiabatic dynamics, or transitionless quantum driving, to quantum open systems whose evolution is governed by a master equation in the Lindblad form. We provide the general framework needed to determine the control strategy required to achieve superadiabaticity. We apply our formalism to two examples consisting of a two-level system coupled to environments with time-dependent bath operators.

We study the relations between classical information and the feasibility of accurate manipulation of quantum system dynamics. We show that if an efficient classical representation of the dynamics exists, optimal control problems on many-body quantum systems can be solved efficiently with finite precision. In particular, one-dimensional slightly entangled dynamics can be efficiently controlled. We provide a bound for the minimal time necessary to perform the optimal process given the bandwidth of the control pulse, which is the continuous version of the Solovay-Kitaev theorem.

Could it be that photosynthetic bacteria have, over millions of years of evolution, learned how to exploit quantum effects to improve the transport of the energy they captured from the sun? Namely, the superpositions offer a faster channelling of this energy across a rather labyrinthical part of the bacteria's photosynthetic complex, after which the energy will eventually be transformed into sugars, allowing the bacteria to grow.

The research activity of this laboratory embraces various aspects of mesoscopic quantum transport in nanostructures and low-dimensional systems: silicon nano-MOSFETs made by state-of-the-art nanofabrication techniques, self-assembled semiconductor nanostructures, carbon nanotubes, superconducting thin films, hybrid systems combining superconductors, normal conductors, and ferromagnets. In these systems we study the physics of individual confined electrons, as well as quantum phenomena resulting from strong electron-electron correlations (e.g.