Qutrit quantum battery: Comparing different charging protocols

Motivated by recent experimental observations carried out in superconducting transmon circuits, we compare two different charging protocols for three-level quantum batteries based on time-dependent classical pulses. In the first case, the complete charging is achieved through the application of two sequential pulses, while in the second the charging occurs in a unique step applying the two pulses simultaneously. The latter approach is characterized by a shorter charging time, and consequently by a greater charging power. Moreover, both protocols are analytically solvable, leading to a complete control on the dynamics of the quantum system and opening unique perspectives in the manipulation of the so-called qutrits. To support this analysis, we have tested both protocols on IBM quantum devices based on superconducting circuits in the transmon regime. The minimum achieved charging time represents one of the fastest stable charging reported so far in solid-state quantum batteries.