We discuss a one-dimensional coupled qubit-array quantum battery model under Born-Karman boundary conditions and investigate both the charging and discharging processes. Applying the stored energy, charging power, and ergotropy as the essential physical indicators of quantum battery, it is observed that minimizing the hopping interaction between the nearest-neighbor qubits in the qubit-array and increasing the number of qubits during battery setup are crucial. Additionally, we employ a classical driving field to optimize battery performance and explore the optimal quantum battery performance by adjusting the driving strength of the classical field. Finally, we have discovered that the initial energy in the charger no longer needs to be higher than the energy in the battery in our protocol, the charger will continue to supply energy to the battery even when there is limited initial available energy in the charger. And the conventional approach of preparing the battery's initial state in its ground state, as observed in previous studies, may not necessarily be the optimal choice. By introducing a strong classical driving field, it is possible to enhance energy storage by allowing for an initial presence of some energy within the battery.
We discuss a one-dimensional coupled qubit-array quantum battery model under Born-Karman boundary conditions and investigate both the charging and discharging processes. Applying the stored energy, charging power, and ergotropy as the essential physical indicators of quantum battery, it is observed that minimizing the hopping interaction between the nearest-neighbor qubits in the qubit-array and increasing the number of qubits during battery setup are crucial. Additionally, we employ a classical driving field to optimize battery performance and explore the optimal quantum battery performance by adjusting the driving strength of the classical field. Finally, we have discovered that the initial energy in the charger no longer needs to be higher than the energy in the battery in our protocol, the charger will continue to supply energy to the battery even when there is limited initial available energy in the charger. And the conventional approach of preparing the battery's initial state in its ground state, as observed in previous studies, may not necessarily be the optimal choice. By introducing a strong classical driving field, it is possible to enhance energy storage by allowing for an initial presence of some energy within the battery.
In this paper, we theoretically investigate the charging dynamics of a closed quantum battery embodied by a four-level atom in a diamond configuration, operating without dissipation. The system is coupled to a single-mode cavity field, which acts as the charger initially prepared in a coherent state, and is simultaneously manipulated by an external classical driving field. By solving the exact system dynamics, we provide a holistic analysis of key performance metrics, including stored energy, ergotropy, energy fluctuations, and von Neumann entropy, as a function of critical system parameters. Our investigation delineates a paramount trade-off; while larger initial charger amplitudes and optimized detunings substantially enhance the stored energy and extractable work, they concurrently amplify fluctuations and entropy, thereby diminishing the battery’s stability and quantum coherence. Crucially, we demonstrate that the coupling to the external drive exhibits a non-monotonic influence, revealing an optimal intermediate regime, specifically at a classical driving strength of λ 2 = 0.5 and detunings δ 1 = δ 3 = 1 ω f , that judiciously balances rapid energy uptake with stable, long-term storage. These results elucidate the complex interplay of coherent control and system parameters, offering critical insights for the rational design of efficient and robust quantum energy storage devices by effectively decoupling charging performance from operational instability.
The performance of open quantum batteries (QBs) is severely limited by decoherence due to the interaction with the surrounding environment. So, protecting the charging processes against decoherence is of great importance for realizing QBs. In this work we address this issue by developing a charging process of a qubit-based open QB composed of a qubit-battery and a qubit-charger, where each qubit moves inside an independent cavity reservoir. Our results show that, in both the Markovian and non-Markovian dynamics, the charging characteristics, including the charging energy, efficiency and ergotropy, regularly increase with increasing the speed of charger and battery qubits. Interestingly, when the charger and battery move with higher velocities, the initial energy of the charger is completely transferred to the battery in the Markovian dynamics. In this situation, it is possible to extract the total stored energy as work for a long time. Our findings show that open moving-qubit systems are robust and reliable QBs, thus making them a promising candidate for experimental implementations.
Charger-mediated quantum batteries offer promising opportunities for efficient energy transfer and storage at the quantum level, with potential advantages beyond their classical counterparts. Here, we theoretically demonstrate that nonlinear charger-battery interactions can substantially accelerate the charging of quantum batteries. In the weak-driving regime, sufficiently strong nonlinear coupling can dominate over the effect of dephasing and significantly reduce the charging time. In the strong- and optimal-driving regimes, where the optimal driving strength maximizes the steady-state ergotropy in the linear-coupling regime, nonlinear coupling gives rise to a new optimum in the charging time beyond that of the linear-coupling regime, accompanied by nearly critically damped dynamics. Remarkably, even in the absence of external driving, nonlinear coupling alone can substantially reduce the charging time, providing an alternative route toward fast battery charging. Our results establish nonlinear charger-battery coupling as an effective resource for accelerating quantum-battery charging and broaden the scope of interaction-enabled quantum advantages in energy transfer and storage.
We discuss how to enhance the charging performance of quantum battery via two entangled auxiliary qubits. The results demonstrate that the quantum battery achieves optimal charging performance when the two auxiliary qubits are in the initial state of maximum entanglement. On this basis, we further discuss the impacts of dissipation and driving strength of the classical field on the charging performance of the quantum battery. It is shown that the quantum battery exhibits higher energy when the dissipation is low. Weak driving strength plays a regulatory role in the energy storage of the quantum battery. Additionally, we compare the performance differences of the quantum battery when the two entangled auxiliary qubits are in different initial states. Our research findings reveal the advantages of entangled auxiliary qubits in enhancing the charging performance of the quantum battery.
We analyze the energy charging of a quantum battery within an open quantum framework, where the interaction between the battery element and an external power source is mediated by an ancilla system acting as a controllable switch. Specifically, we investigate the charging and discharging dynamics of a cavity-based quantum battery coupled to a driven qubit functioning as the charger. To ensure lossless power transfer, we utilize an adiabatic evolution protocol. Furthermore, we implement counterdiabatic driving, achieved by applying an auxiliary control field to the original Hamiltonian, to suppress undesired transitions and realize fast adiabatic dynamics. This scheme significantly accelerates the charging process. We demonstrate that the charging efficiency under adiabatic evolution is enhanced and exhibits stable, non-oscillatory behavior, and we determine the optimal duration for the operation. Finally, we show that counterdiabatic driving minimizes the path length between the initial and final states, inducing the shortest possible evolution distance.
In the context of quantum information , a quantum battery refers to a system composed of quantum particles that can store and release energy in a way that is governed by the principles of quantum mechanics . The study of open quantum batteries is motivated by the fact that real-world quantum systems are almost never perfectly isolated from their environment. One important challenge in the study of open quantum batteries is to develop theoretical models that accurately capture the complex interactions between the battery and its environment. The goal of studying open quantum batteries is to develop practical methods for building and operating quantum devices that can store and release energy with high efficiency and reliability, even in the presence of environmental noise and other sources of decoherence. In this study, we will investigate the impact of the classical driving field on the charging and discharging processes of open quantum batteries. The application of a classical driving field can effectively regulate the charging and discharging processes of a battery, resulting in enhanced performance and increased efficiency. It will also be demonstrated that the efficiency of open quantum batteries is influenced by the detuning between the qubit and the classical driving field, as well as by the detuning between the central frequency of the cavity and the classical driving field.