Collective enhancement in dissipative quantum batteries

We study a quantum battery made out of $N$ non-mutually interacting qubits coupled to a dissipative single electromagnetic field mode in a resonator. We quantify the charging energy, ergotropy, transfer rate, and power of the system, showing that collective enhancements are still present despite of losses, and can even increase with dissipation. Moreover, we observe that a performance deterioration due to dissipation can be reduced by scaling up the battery size. This is useful for experimental realizations when controlling the quality of the resonator and the number of qubits are limiting factors.Comment: Main content: 4.5 pages and 5 figures. Appendix content: 7 pages and 6 figures. In total (including references): 13 pages and 11 figures. Manuscript accepted to publish in Physical Review