Speaker: Gian Marcello Andolina
Time: 2018-08-23 11:00-2018-08-23 14:00
Venue: MMW S327
Quantum phenomena, such as phase coherence and entanglement, constitute remarkable resources that may enable superior performances of future technological devices. Given this context, a number of researchers has been working on “quantum batteries”, i.e. quantum mechanical systems for storing energy where genuine quantum effects can be used to obtain more efficient and faster charging processes with respect to classical analog systems.
In the first part of the talk i present a a model of a QB that can be engineered in solid-state architectures. It consists of N two-level systems coupled to a single photonic mode in a cavity. We contrast this collective model (“Dicke QB”), whereby entanglement is genuinely created by the common photonic mode, to the one in which each two-level system is coupled to its own separate cavity mode (“Rabi QB”). By employing exact diagonalization, we demonstrate the emergence of a quantum advantage in the charging power of Dicke QBs, which scales like √ N for N \gg1.
In the second part of this talk we introduce new figures of merit to quantify the performance of a quantum battery, by assessing the problem of work extraction from a battery after a charging process. A good battery should be able to provide energy to other devices. It is known that producing correlations between systems has a cost in terms of extractable work, while it is believed that in certain cases producing correlations during the dynamics is the key effect to speed up the charging of a battery. We will study such competition in a Tavis-Cummings model of a quantum battery, which can be realized experimentally by coupling in a resonant fashion a photonic cavity to N qubits.
References: 1. Dario Ferraro, Michele Campisi, Gian Marcello Andolina, Vittorio Pellegrini, Marco Polini, Phys. Rev. Lett. 120, 117702 (2018).
2. Gian Marcello Andolina, Maximilian Keck, Andrea Mari, Michele Campisi, Vittorio Giovannetti, Marco Polini, arXiv:1807.08656.
3. Gian Marcello Andolina, Donato Farina Andrea Mari, Vittorio Pellegrini, Vittorio Giovannetti, and Marco Polini, arXiv:1807.04031.
Gian Marcello Andolina is currently a PhD student at Scuola Normale Superiore in Pisa, Italy under the supervision of Marco Polini and Vittorio Giovannetti; His PhD research directions cover topological systems and quantum thermodynamics, in particular quantum batteries.