& lead Physics 17, s58
Connecting the charger and battery to a common tank causes a direct flow of power to the battery.
Figure Credit: S. Barzanjeh/University of Calgary; B. Ahmadi/University of Gdansk
Like any other battery, a quantum battery is a device that stores energy. But unlike its electrochemical counterparts, which are charged by streams of electrons, a quantum battery is powered by photons. Effects such as quantum entanglement and quantum coherence mean that a quantum battery can be charged faster as you add more cells (see Viewpoint: Scale up the potential of quantum batteries). Shabir Barzanjeh at the University of Calgary, Canada, and colleagues now propose a charging protocol for a quantum battery that maximizes stored energy while minimizing energy dissipation during charging [1]. The innovation lies in promoting non-reciprocity, an invaluable element in optical and microwave signal processing that allows light to propagate asymmetrically along opposite directions.
A quantum battery charging system could potentially be built using any time-reversal symmetry-breaking quantum system. Barzanjeh’s version combines a charger (which can be realized by a microwave resonator) with a battery (which can be realized by a mechanical oscillator). An external pump supplies the photon energy that is exchanged between the battery and the charger. Unlike most quantum battery designs, the charger and battery are simultaneously connected to a common tank. This results in an interference-like phenomenon, where the coherent coupling between the charger and the battery introduces a non-reciprocal current within the system. This counteracts dissipative interactions with the battery’s surroundings, improving energy transfer efficiency.
The researchers calculate a fourfold increase in the energy stored in the battery during charging compared to conventional charging. They say their version will lead to a quantum battery that has a higher capacity than those previously proposed or implemented. Their design works with both optical and microwave photons, making it compatible with superconducting qubits, nanoelectronics and nanophotonics.
Rachel Berkowitz
Rachel Berkowitz is a corresponding editor forJournal of Physics based in Vancouver, Canada.
References
- B. Ahmadi et al.Nonreciprocal quantum batteries, Phys. Rev. Lett. 132210402 (2024).
Subject areas
#charge #quantum #battery
Image Source : physics.aps.org