Exploiting quantum effects for energy storage, quantum batteries (QBs) offer compelling advantages over conventional ones in terms of superior energy density, ultrafast charging, and high conversion efficiency. However, their realization is hampered by decoherence, which causes incomplete charging, rapid self-discharging, and reduced extractable work. Here, we propose a QB architecture based on a chiral magnonic platform. It comprises two yttrium iron garnet (YIG) spheres, one serving as the charger and the other as the QB, coupled to a waveguide. The unique chiral coupling between magnons and the guided electromagnetic fields breaks inversion symmetry, inducing both nonreciprocal energy flow and coherent interference between the charger and QB. Their synergy endows our QB with a 34-fold increase in energy capacity and a 55-fold boost in extractable work compared to its achiral counterpart in an experimentally accessible regime. Our scheme harnesses the decoherence from the electromagnetic fields and turns its destruction into an asset, which enables the robustness and wireless-like remote charging features of the QB. Our analysis reveals that these extraordinary capabilities stem from quantum coherence. By establishing chirality as a useful quantum resource, our work paves a viable path toward the realization of QBs.
Exploiting quantum effects for energy storage, quantum batteries (QBs) offer compelling advantages over conventional ones in terms of superior energy density, ultrafast charging, and high conversion efficiency. However, their realization is hampered by decoherence, which causes incomplete charging, rapid self-discharging, and reduced extractable work. Here, we propose a QB architecture based on a chiral magnonic platform. It comprises two yttrium iron garnet (YIG) spheres, one serving as the charger and the other as the QB, coupled to a waveguide. The unique chiral coupling between magnons and the guided electromagnetic fields breaks inversion symmetry, inducing both nonreciprocal energy flow and coherent interference between the charger and QB. Their synergy endows our QB with a 34-fold increase in energy capacity and a 55-fold boost in extractable work compared to its achiral counterpart in an experimentally accessible regime. Our scheme harnesses the decoherence from the electromagnetic fields and turns its destruction into an asset, which enables the robustness and wireless-like remote charging features of the QB. Our analysis reveals that these extraordinary capabilities stem from quantum coherence. By establishing chirality as a useful quantum resource, our work paves a viable path toward the realization of QBs.
The quantum battery (QB) makes use of quantum effects to store and supply energy, which may outperform its classical counterpart. However, there are two challenges in this field. One is that the environment-induced decoherence causes the energy loss and aging of the QB, the other is that the decreasing of the charger-QB coupling strength with increasing their distance makes the charging of the QB become inefficient. Here, we propose a QB scheme to realize a remote charging via coupling the QB and the charger to a rectangular hollow metal waveguide. It is found that an ideal charging is realized as long as two bound states are formed in the energy spectrum of the total system consisting of the QB, the charger, and the electromagnetic environment in the waveguide. Using the constructive role of the decoherence, our QB is immune to the aging. Additionally, without resorting to the direct charger-QB interaction, our scheme works in a way of long-range and wireless-like charging. Effectively overcoming the two challenges, our result supplies an insightful guideline to the practical realization of the QB by reservoir engineering.
As a quantum thermodynamic device that utilizes quantum systems for energy storage and delivery, the quantum battery (QB) is expected to offer revolutionary advantages in terms of increasing the charging power and the extractable work by using quantum resources. However, the ubiquitous decoherence in the microscopic world inevitably forces the QB to spontaneously lose its stored energy. This is called the self-discharging of the QB and severely limits its realization. We propose a QB scheme based on the nitrogen-vacancy center in diamond, where the electronic spin serves as the QB. Inspired by our finding that the coherent ergotropy decays more slowly than the incoherent ergotropy, we reveal a mechanism to enhance the inherent robustness of the QB to the self-discharging by improving the ratio of coherent ergotropy to total ergotropy. The unique hyperfine interaction between the electron and the native ^{14}N nucleus in our scheme allows one to coherently optimize this ratio. Mitigating the self-discharging and optimizing the extractable work simultaneously, our results pave the way for the practical realization of the QB.
With intensive studies of quantum thermodynamics, quantum batteries (QBs) have been proposed to store and transfer energy via quantum effects. Despite many theoretical models, decoherence remains a severe challenge and practical platforms are still rare. Here, we propose a QB based on the coherent Ising machine, in which the signal field acts as the core energy-storage unit. To clarify the role of quantum coherence in resisting dissipation, we decompose the ergotropy, i.e., the maximum extractable work from the QB, into its coherent and incoherent components. We find that the coherent part decays at a rate roughly half that of the incoherent part, exhibiting much stronger robustness against decoherence. More importantly, the coherent ergotropy and the average charging power reach their respective maxima at essentially the same moment, which defines the optimal instant to switch off the pump field. Finally, by coupling the QB to a two-level system as the load, we demonstrate an efficient energy discharge process of the proposed QB. Our work establishes a realistic and immediately-implementable QB architecture on a mature optical platform, laying a foundation for experimental exploration of quantum energy storage.
Environmentally induced decoherence leads to irreversible energy loss during the active charging and discharging processes of quantum batteries (QBs). To address this issue, we propose a charging protocol utilizing the nonlocal coupling properties of giant atoms (GAs). In this Letter, both the QB and its charger are implemented as superconducting GAs with multiple nonlocal coupling points to a shared microwave waveguide. By engineering these atoms in a braided configuration, where their coupling paths are spatially interleaved, we realize lossless energy transfer dynamics. This is achieved by exploiting destructive interference to suppress waveguide-mediated dissipation while simultaneously preserving coherent interactions between the charger and the QB. The charging properties of separated and nested coupled configurations are also investigated. The results show that these two configurations underperform the braided configuration. Additionally, we propose a long-range chiral charging protocol that facilitates unidirectional energy transfer between the charger and the battery, with the capability to reverse the flow direction by modulating the applied magnetic flux. Our results provide guidelines for implementing a decoherence-resistant charging protocol and remote chiral QBs in circuits with GA engineering.
Quantum batteries (QB), as an energy storage and transfer device, not only show obvious advantages compared to classical electrochemical batteries, but also have important applications in quantum information. Self-discharging is a central obstacle to storing useful work in open QB, especially when the charger itself provides an unavoidable loss channel. Here we show that such charger-induced loss can be converted into a protection mechanism by combining Purcell effect with quantum Zeno effect. We reveal that the virtual photon process and the Purcell effect can induce the strong coupling regime to the quantum Zeno regime, in which the stronger the dissipation of the charger, the weaker the self-discharging effect of the QB. As a result, the dissipation caused by the charger to the QB can be suppressed four orders of magnitude in our scheme. Meanwhile, the quantum Zeno effect induced by the Purcell effect can also avoid the energy backflow between the QB and the charger. Owing to the significantly suppressed dissipation, the stored energy of QB can be charged to a nearly full state and the stored energy is almost converted into extractable work, which greatly improves the energy conversion efficiency.
Nowadays, quantum batteries (QBs) have been designed to outperform their classical counterparts by leveraging quantum advantages. For instance, the charging power greatly benefits from the entanglement generation of a collective charging scheme (e.g., the Dicke QB), especially in the ultrastrong coupling (USC) regime or even larger. However, apart from the fragility of the QB under intrinsic decoherence effects, another critical drawback emerges inevitably. Specifically, the non-negligible counter-rotating (CR) term in the USC regime would induce coherence in the energy basis of QB, thus remarkably degrading the charging efficiency. To tackle these challenges, we propose a high-efficiency and noise-immune QB boosted by dynamical modulation. It is demonstrated that the time-varying modulation can effectively reduce the CR coupling, resulting in a notable improvement in charging efficiency. Particularly, for a judicious choice of modulation parameters that entirely eliminate the CR interaction, the Dicke QB can be charged optimally, resembling the behavior of the Tavis-Cummings QB. In the subsequent storage process, beyond the natural robustness to pure dephasing noise, our scenario is also highly resilient to the dissipation noise and thus can achieve perfect energy storage by effective bath engineering. While feasible with current experimental platforms, our proposal offers a solid foundation for the implementation of a powerful QB and may drastically promote the development of energy storage and delivery techniques in the future.