Quantum Battery Based on Superabsorption

A quantum battery is a device where an energy is charged by using a quantum effect. Here, we propose a quantum battery with a charger system composed of $N$ qubits by utilizing a collective effect called a superabsorption. Importantly, the coupling strength between the quantum battery and charger system can be enhanced due to an entanglement. While the charger time scales as $\Theta\left(N^{-1/2}\right)$ by applying a conventional scheme, we can achieve a charging time $\Theta\left(N^{-1}\right)$ in our scheme. Our results open the path to ultra-fast charging of a quantum battery.