(Thermo‐)Dynamics of the Spin‐Boson Model in the Weak Coupling Regime: Application as a Quantum Battery

ABSTRACT The spin‐boson model's dynamical and thermodynamic features in the weak coupling regime are investigated using the weak coupling spin‐boson (WCSB) and phase covariant (PC) master equations. Both unital (pure dephasing) and non‐unital (dissipative) quantum channels are considered. On the dynamical side, key quantum features including non‐Markovianity, quantum speed limit, quantum coherence, and the system's steady‐state behavior, are explored. Notably, the measures of non‐Markovianity exhibit different behavior under WCSB and PC dynamics. From the quantum thermodynamic perspective, the spin‐boson system is conceptualized as a quantum battery and analyze its performance through metrics such as energy, ergotropy, anti‐ergotropy, and battery capacity. The roles of pure dephasing and dissipative processes in shaping the battery's performance are further examined. The findings demonstrate the spin‐boson model's versatility as a platform for efficient energy storage and transfer in quantum thermodynamic devices.