Genuine Quantum Advantage in Anharmonic Bosonic Quantum Batteries

Finding a quantum battery model that displays a genuine quantum advantage, while being prone to experimental fabrication, is an extremely challenging task. In this Letter we propose a deceptively simple quantum battery model that displays a genuine quantum advantage, saturating the quantum speed limit. It consists of two harmonic oscillators (the charger and the battery), coupled during the charging dynamics by an anharmonic interaction. We first present the model, then certify the genuine quantum advantage, and finally briefly discuss how the battery can be fabricated through the use of superconducting circuits.