Seminar by Giuliano Benenti (U. dell'Insubria)

The development of fast and efficient quantum batteries is crucial for the prospects of quantum technologies. We show that both requirements are accomplished in the paradigmatic model of a harmonic oscillator strongly coupled to a highly non-Markovian thermal reservoir. At short times, a dynamical blockade of the reservoir prevents the leakage of energy towards its degrees of freedom, promoting a significant accumulation of energy in the battery with high efficiency. The evolution of the energy stored in the battery is almost periodic, which allows to avoid a too precise fine-tuning of the time at which the battery need to be disconnected from the charger. Moreover, our protocol is very efficient, allowing in principle to extract through unitary operations practically all the energy stored in the quantum battery, with a ratio between the energy that can be extracted and the work done by the charger which approaches the ideal unit limit. Our protocol may be envisioned with a quantum LC circuit playing the role of the battery and with the required environment being suitably engineered via state–of–the–art quantum circuits.