Giant-Atom Quantum Batteries

Abstract

Environmentally induced decoherence poses a fundamental challenge to quantum energy storage systems, causing irreversible energy dissipation and performance aging of quantum batteries (QBs). To address this issue, we propose a QB protocol utilizing the nonlocal coupling properties of giant atoms (GAs). In this architecture, 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 show the emergence of decoherence-immune interaction dynamics. This unique geometry enables destructive interference between decoherence channels while preserving coherent energy transfer between the charger and the QB, thereby effectively suppressing the aging effects induced by waveguide-mediated dissipation. The charging properties of separated and nested coupled configurations are investigated. The results show that these two configurations underperform the braided configuration. Additionally, we propose a long-range chiral charging scheme 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 result provides guidelines for implementing a decoherence-resistant charging protocol and remote chiral QBs in circuits with GAs engineering.

Figures (3)

• Figure 1: Schematics of the (a) braided; (b) separated; (c) nested configurations for double two-level giant atoms with energy separation $\omega_{0}$ interacting with a common waveguide. (d) Schematic diagram of our remote chiral charging protocol. The phases $\theta_{1,2}^{a(b)}$ are modulated by the external magnetic flux.
• Figure 2: (a1)-(c1) Exchange interaction $g_{ab}$ (red solid curve), individual decay rate $\Gamma_{a}$ (blue dashed curve), individual decay rate $\Gamma_{b}$ (green dotted curve), and collective decay rate $\Gamma_{\rm coll}$ (black dash-dot curve) as a function of $\theta$ for the braided (a1), separated (b1), and nested (c1) coupling configuration. (a2)-(c2) Ergotropy $\mathcal{E}$, (a3)-(c3) Fluctuations $\Sigma$, and (a4)-(c4) Average charging power $\mathcal{P}$, as functions of the scaled charging time $\omega_{0}t$ and the accumulated phase $\theta$. The parameter $\gamma=0.1\omega_{0}$.
• Figure 3: (a) Dissipation of the two separated GAs with the propagation time $\tau = 10\Gamma_{\rm max}$. (b) Ergotropy $\mathcal{E}$, (c) Fluctuations $\Sigma$, and (d) Average charging power $\mathcal{P}$, as functions of the scaled charging time $\Gamma_{\rm max}t$.