  We propose novel charging protocols for quantum batteries based on quantum
superpositions of trajectories. Specifically, we consider that a qubit (the
battery) interacts with multiple cavities or a single cavity at various
positions, where the cavities act as chargers. Further, we introduce a quantum
control prepared in a quantum superposition state, allowing the battery to be
simultaneously charged by multiple cavities or a single cavity with different
entry positions. To assess the battery's performance, we evaluate the maximum
extractable work, referred to as ergotropy. Our main result is that the
proposed protocols can utilize quantum interference effects to speed up the
charging process. For the protocol involving multiple cavities, we observe a
substantial increase in ergotropy as the number of superposed trajectories
increases. In the case of the single-cavity protocol, we show that two
superposed trajectories (entry positions) are sufficient to achieve the upper
limit of the ergotropy throughout the entire charging process. Furthermore, we
propose circuit models for these charging protocols and conduct
proof-of-principle demonstrations on IBMQ and IonQ quantum processors. The
results validate our theoretical predictions, demonstrating a clear enhancement
in ergotropy.
