Enhancing ultracold atomic batteries using tunable interactions

We study the charging performance of a one-dimensional, many-body bosonic quantum battery driven by a harmonic-oscillator charger, focusing on how many-body effects and intra-species interactions influence the energy-transfer dynamics. We show that by tuning the charger frequency, the system can reach a resonance condition where perfect energy transfer and maximal extractable work are achieved. In the weak-coupling limit this can be understood by approximating the battery-charger dynamics using an effective two-level model, which accurately predicts the maximum stored work, ergotropy, and optimal charging time. In this regime, many-body batteries exhibit enhanced charging power, reduced quantum speed limit (QSL) times, and comparable or lower irreversible work relative to single-particle batteries. We further examine the role of intra-species interactions: repulsive interactions inside the battery medium suppress performance, whereas attractive interactions can significantly enhance it, with both types of interactions generating additional charging resonances. Our results show that particle number and interaction control provide powerful tools for designing fast, efficient, and scalable quantum batteries, and point toward a feasible experimental implementation in ultracold-atom platforms.