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.
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.
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.
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.
Remote quantum batteries require directional and controllable energy transfer between spatially separated quantum nodes, yet most existing protocols rely on direct charger-battery Hamiltonian couplings. Here we propose a phase-tunable waveguide-QED architecture for remote quantum-battery charging, in which a driven charger and a remote battery are coupled solely via engineered waveguide-mediated interference, without any direct local interaction. We systematically compare four configurations: two-giant-emitter and giant-small-emitter hybrids, each with open or mirror-terminated waveguides. By engineering the propagation and coupling phases, the waveguide-mediated coherent exchange interaction and collective dissipation can be balanced to suppress the backward channel while retaining a finite forward channel, thereby realizing cascaded-like unidirectional charging. Our analysis shows that nonreciprocity and storage efficiency can be independently engineered, offering design flexibility for different quantum network scenarios. The giant-small-emitter mirror-terminated configuration simultaneously achieves perfect nonreciprocity and battery-dominated storage, while both giant-small-emitter configurations exhibit distance-insensitive directionality. Extending the scheme to quadratic driving, we show that anomalous second moments render the battery state non-passive, making ergotropy a performance metric distinct from stored energy. These results establish phase-tunable waveguide networks as a versatile platform for remote quantum-energy transfer and provide design principles for directional and work-extractable energy storage in quantum networks.
Currently, remote energy transfer and immunity to dissipation are hot topics in quantum batteries (QBs). In this work, we propose a protocol to realize energy transfer between two remote atoms (a quantum charger and a quantum battery) each coupled to a separate optical cavity with the cavities connected by a fiber. The cavities and fiber are coupled to their individual baths. After optimizing inter-system couplings to achieve an efficient transfer, we uncover the effect of suppressing dissipation by introducing parity deformation of the cavities fields. We also prove that the charger-battery entanglement is a consumable resource for energy storage: it is initially stored until the charger and battery reach energy balance, and then subsequently consumed to maintain the increase in energy stored in the battery. The present scheme is the first execution of energy transfer to a distant battery assisted by entanglement, which may help better understand quantum thermodynamics and open new possibilities toward harnessing decoherence as a resource to improve the charging performance of QBs.
Abstract We propose a scheme to achieve a nonreciprocal quantum battery (QB) in the non-Hermitian (NH) system, which can overcome the intrinsic dissipation and reverse flow constraints. The design is based on a charger and a battery, which are coherently coupled and jointly interact with a bad cavity. By introducing the auxiliary bad cavity and exploiting the nonreciprocal condition, this model can harness the environmental dissipation to suppress the reverse energy transfer. Under resonant conditions, we have achieved a four ratio of the battery energy to the charger energy; in contrast, this ratio is significantly reduced under large detuning. Through damping optimization, high efficiency of the short-time charging power is attained. In comparison to the fully nonreciprocal scheme, the QB operating at the exceptional point (EP) exhibits greater resilience to parameter fluctuations. These findings highlight the potential of NH quantum engineering for advancing QB technology, particularly in regimes involving directional energy transfer, controlled dissipation, and entropy management in open quantum systems.
We propose a scheme to achieve a nonreciprocal quantum battery (QB) in the non-Hermitian (NH) system, which can overcome the intrinsic dissipation and reverse flow constraints. The design is based on a charger and a battery, which are coherently coupled and jointly interact with a bad cavity. By introducing the auxiliary bad cavity and exploiting the nonreciprocal condition, this model can harness the environmental dissipation to suppress the reverse energy transfer. Under resonant conditions, we have achieved a four ratio of the battery energy to the charger energy; in contrast, this ratio is significantly reduced under large detuning. Through damping optimization, high efficiency of the short-time charging power is attained. In comparison to the fully nonreciprocal scheme, the QB operating at the exceptional point (EP) exhibits greater resilience to parameter fluctuations. These findings highlight the potential of NH quantum engineering for advancing QB technology, particularly in regimes involving directional energy transfer, controlled dissipation, and entropy management in open quantum systems.