Energy-invariant catalysis of stable ergotropy in strongly coupled spin-chain quantum batteries

Abstract Achieving rapid and stable energy storage in quantum batteries (QBs) remains a key challenge, particularly under strong system-environment coupling where non-Markovian effects become prominent. While most previous studies focus on weak coupling regimes, we propose a many-body QB model exhibiting collective charging and discharge suppression in a non-perturbative regime. The model adopts a Λ-type configuration where multiple battery units share a common excited state and have individual ground states, forming an effective collective structure. To accurately capture the dynamics under strong coupling, the system’s time evolution is governed by a Redfield-type master equation incorporating memory effects via a Debye spectral density. We quantify the stored energy using ergotropy and analyze the impact of tunneling, driving strength, spectral width, and environmental temperature on charging performance. Numerical simulations reveal that optimized driving and reservoir engineering can simultaneously achieve rapid and stable charging while suppressing energy leakage. These results provide theoretical insights into strong-coupling thermodynamics and guide the design of robust QB platforms using solid-state or atomic systems.