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.
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.
Abstract Coupling with an external environment inevitably affects the dynamics of a quantum system. Here, we consider how charging performances of a quantum battery, modelled as a two level system, are influenced by the presence of an Ohmic thermal reservoir. The latter is coupled to both longitudinal and transverse spin components of the quantum battery including decoherence and pure dephasing mechanisms. Charging and discharging dynamics of the quantum battery, subjected to a static driving, are obtained exploiting a proper mapping into the so-called spin-boson model. Analytic expressions for the time evolution of the energy stored in the weak coupling regime are presented relying on a systematic weak damping expansion. Here, decoherence and pure dephasing dissipative coupling are discussed in details. We argue that the former results in better charging performances, showing also interesting features reminiscent of the Lamb shift level splitting renormalization induced by the presence of the reservoir. Charging stability is also addressed, by monitoring the energy behaviour after the charging protocol has been switched off. This study presents a general framework to investigate relaxation effects, able to include also non Markovian effects, and it reveals the importance of controlling and, possibly, engineering system-bath coupling in the realization of quantum batteries.
In this work, we introduce a method for deriving exact master equations from the dynamical map for finite open quantum systems coupled to (in)finite reservoirs, using the principle of minimal dissipation. The exact dynamics of the central spin model, which models a finite-bath open quantum system, is developed for two interaction types: Heisenberg and stochastic pure-dephasing interactions. The Heisenberg interaction yields a novel phase-covariant quantum channel in the strong-coupling regime, offering a new platform for studying a range of quantum information protocols. The stochastic pure-dephasing interaction provides the microscopic derivation of the paradigmatic non-Markovian random telegraph noise (RTN) channel, establishing its quantum foundation and offering insight into stochastic couplings. We derive the closed-form master equations for both models. As a demonstration, we explore the thermodynamic performance of these systems as quantum batteries. A direct relationship between quantum heat current and charging power is revealed, and RTN quantum batteries are shown to have advantages in charge storage.
ABSTRACT This study investigates the charging performance of single‐qubit and multi‐qubit quantum batteries in both Markovian and non‐Markovian environments. Using the collision model to simulate a bosonic bath, we provide a detailed study of the impact of temperature on battery performance through both analytical and numerical solutions in a prepared thermal bath, demonstrating that high temperature generally suppresses steady‐state ergotropy of quantum batteries, while also accelerating the convergence to the steady state. By applying the Luo‐Fu‐Song measure of non‐Markovianity, it is found that the information backflow generated in a non‐Markovian environment further enhances the battery's ergotropy and speeds up the approach to the steady state. Additionally, when studying multi‐qubit quantum battery, we consider each individual spin as an independent battery unit. The results show that non‐Markovian memory effects allow spins directly coupled to the bath to store more energy. Notably, with elevated temperature even enhancing their steady‐state ergotropy due to information backflow. Finally, we find that the battery's mixedness is always positively correlated with the unavailable energy. This provides theoretical support for distributed energy extraction in quantum batteries.
Abstract This study explores the energy storage dynamics of a quantum battery (QB) modeled using a dipolar spin system with Dzyaloshinskii–Moriya (DM) interaction. We examine the performance of this system in terms of ergotropy, instantaneous power, capacity, and quantum coherence using a two-qubit model. By solving the system’s time evolution under cyclic unitary processes, we analyze how external parameters such as temperature, magnetic field, and DM interaction influence the charging behavior and quantum resources of the battery. The findings demonstrate that quantum coherence and DM interaction significantly enhance the energy storage efficiency and power output of the quantum battery, offering promising strategies for designing high-performance quantum energy storage devices. Furthermore, we investigate the performance of quantum battery under the influence of a common dephasing environment, which limits the long-term work-extraction capability of dipolar quantum batteries.
This study explores the energy storage dynamics of a quantum battery (QB) modeled using a dipolar spin system with Dzyaloshinskii-Moriya (DM) interaction. We examine the performance of this system in terms of ergotropy, instantaneous power, capacity, and quantum coherence using a two-qubit model. By solving the system's time evolution under cyclic unitary processes, we analyze how external parameters such as temperature, magnetic field, and DM interaction influence the charging behavior and quantum resources of the battery. The findings demonstrate that quantum coherence and DM interaction significantly enhance the energy storage efficiency and power output of the quantum battery, offering promising strategies for designing high-performance quantum energy storage devices. Furthermore, we investigate the performance of quantum battery under the influence of a common dephasing environment, which limits the long-term work-extraction capability of dipolar quantum batteries.
Here, we study the impact of non-Markovian evolution on prominent characteristics of quantum thermodynamics such as ergotropy and power. These are benchmarked by the behavior of the quantum speed limit time. We make use of both geometric-based, particularly the quantum Fisher and Wigner–Yanase information metric, and physical properties-based measures, particularly the relative purity measure and relative entropy of coherence measure, to compute the quantum speed limit time. A simple non-Markovian model of a qubit in a bosonic bath exhibiting non-Markovian amplitude damping evolution is considered, which, from the quantum thermodynamic perspective with finite initial ergotropy, can be envisaged as a quantum battery. To this end, we explore the connections between the physical properties-based measures of the quantum speed limit time and the coherent component of ergotropy. The non-Markovian evolution is shown to impact the recharging process of the quantum battery. Furthermore, a connection between the discharging–charging cycle of the quantum battery and the geometric measures of the quantum speed limit time is observed.