This study investigates the dynamical behaviour of a two-cell (two-atom) quantum battery driven by a two-mode charging field. We explore the influence of varying interaction strengths on the system?s performance. This includes increasing the coupling between cells and charging fields, and cells themselves through a dipole interaction and Ising interaction along the z-axis. Additionally, the impact of environmental effects is examined by incorporating decay terms for both the charging fields and the cells. Our analysis focuses on key performance metrics such as stored energy, average power, ergotropy, energy fluctuations, and quantum speed limit time. The results reveal that the environment negatively impacts stored energy, power, and ergotropy, but leads to higher speed limits. Enhanced coupling between the charging fields and the cells improves the studied correlations, promoting efficient energy transfer and decreasing speed limit time. Increasing the coupling between the cells, either via the dipole or Ising interaction, generally exhibits a similar effect. This involves a decrease in maximum achievable energy storage, accompanied by the emergence of more erratic energy fluctuations.
This study investigates the dynamical behaviour of a two-cell (two-atom) quantum battery driven by a two-mode charging field. We explore the influence of varying interaction strengths on the system?s performance. This includes increasing the coupling between cells and charging fields, and cells themselves through a dipole interaction and Ising interaction along the z-axis. Additionally, the impact of environmental effects is examined by incorporating decay terms for both the charging fields and the cells. Our analysis focuses on key performance metrics such as stored energy, average power, ergotropy, energy fluctuations, and quantum speed limit time. The results reveal that the environment negatively impacts stored energy, power, and ergotropy, but leads to higher speed limits. Enhanced coupling between the charging fields and the cells improves the studied correlations, promoting efficient energy transfer and decreasing speed limit time. Increasing the coupling between the cells, either via the dipole or Ising interaction, generally exhibits a similar effect. This involves a decrease in maximum achievable energy storage, accompanied by the emergence of more erratic energy fluctuations.
Abstract This study investigates the dynamics of quantum batteries (QBs), focusing on the pivotal role of quantum entanglement in mediating inter-cellular energy transfer within a two-cell configuration (two-qubit), wherein one cell is directly coupled to the charging source. Employing the Lindblad master equation to model the system’s evolution, the influence of coherent state amplitudes, detuning, inter-cellular coupling strength, and dissipation rates on stored energy, ergotropy, energy fluctuations, concurrence-quantified entanglement, and their parametric interrelations is scrutinized. Our results indicate a direct correlation between the entanglement qubits and the efficiency of energy transfer. In particular, stronger entanglement between the primary cell, which is connected to the charger, and the secondary cell leads to more energy transfer. Consequently, entanglement significantly improves energy transfer between the two qubits.
How to improve charging processes and suppress self-discharging processes has always been one of the key issues to achieve quantum batteries with high performance. Although a quantum battery is inevitably influenced by composite environments, this situation is still little understood, particularly regarding the influence of the memory effect of the composite environments and the coupling between composite environments. In this work, we investigate the effects of the composite environments, composed of two identical parts each containing a single cavity mode decaying to a reservoir, on the charging and self-discharging processes of a quantum battery. We show that increasing the two-mode coupling can effectively enhance the charging performance (i.e., the stored energy, the charging power, ergotropy) and restrain the self-discharging process (i.e., suppressing the process of dissipating the energy). However, different from the effect of two-mode coupling, we reveal that the memory effect of the reservoir in this composite environment is unfavorable to the charging process of the quantum battery, which is in sharp contrast to previous studies where the memory effect can significantly improve the charging performance of a quantum battery. Our results may benefit to the realization of quantum batteries with high performance under the actual complex environmental noise.
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.
Abstract Quantum batteries (QBs) have been proposed as devices that exploit the advantage of quantum resources, such as coherence and entanglement, to improve charging performance. In this study, we theoretically investigate a QB model based on two coupled double quantum dots (TDQDs) implemented on the well-established AlGaAs/GaAs platform for quantum nanodevice fabrication. Using ergotropy and power as key performance indicators, we examine how various system parameters affect the energy performance of the QB. Our study begins with an analysis of quantum resources in the QB’s initial state, followed by an examination of how control parameters that influence these resources impact the modeling and performance of the battery. Our results demonstrate that increasing the energy offset improves ergotropy and power but reduces quantum correlations. Conversely, increasing tunneling couplings leads to a non-monotonic variation in the maximum ergotropy, which peaks at a certain point before decreasing, closely following the behavior of quantum entanglement despite continued growth in quantum coherence. This highlights the feasibility of efficient energy storage in quantum dots (QDs) for use in quantum batteries (QBs). It also emphasizes that coherence alone is insufficient for optimal performance and that other quantum correlations are necessary and must be carefully considered to fully exploit the potential of quantum resources.
Abstract Quantum batteries harness quantum coherence and entanglement to achieve efficient energy storage beyond classical limits. This study presents a comparative analysis of series and parallel charging protocols, evaluating their impact on charging efficiency, stability, and dissipation. Using the Lindblad master equation, we investigate the effects of multi-photon interactions, cavity decay, atomic relaxation, and thermal fluctuations on the evolution of key physical quantities, including stored energy, ergotropy, and entropy of the charger. Our findings reveal that parallel charging exhibits superior stability, reduced entropy fluctuations, and higher ergotropy, while series charging suffers from increased dissipation and oscillatory instabilities. These insights contribute to the development of high-performance quantum energy storage systems for advanced quantum technologies.
ABSTRACT We investigate a quantum battery within an open quantum system, in which a harmonic oscillator acts as the charger and two‐level atoms serve as battery cells. This model accounts for the dissipative effects arising from the coupling between both the charger and battery cells with the environment. By analyzing the time evolution of the battery energy, charging power, ergotropy, and logarithmic negativity, we systematically examine the influence of the number of battery cells and environmental dissipation on battery performance. Our results show that increasing significantly enhances the charging power, exhibiting a collective enhancement effect. Both the atomic number and environmental dissipation strongly affect the ergotropy per atom, but their influences are distinct.