Harnessing Environmental Noise for Quantum Energy Storage

TL;DR

This work demonstrates a drive-free quantum battery powered solely by environmental noise through collective dissipation. By modeling an ensemble of $N$ identical two-level systems coupled collectively to a thermal reservoir, the authors show that interference between emission and absorption channels, encoded by the collective jumps $J_\pm$, steers the system into a non-passive steady state with finite ergotropy, with the extractable work increasing with $N$. The steady-state structure is analyzed via Schur–Weyl duality, revealing a block-diagonalLiouvillian with surviving $j$ sectors; robustness to partial collectivity and finite-temperature optima are established, including a detailed balance between collective pumping and local which-path information. These results suggest a scalable, drive-free quantum battery compatible with circuit- and cavity-QED platforms, with potential applications in ancilla resets, stabilizer pumps, and fault-tolerant architectures. The study provides both conceptual advances in quantum thermodynamics and a practical blueprint for autonomous quantum batteries powered by thermal environments.

Abstract

Quantum hardware increasingly relies on energy reserves that can later be converted into useful work; yet, most battery-like proposals demand coherent drives or engineered non-equilibrium resources, limiting practicality in noisy settings. We develop an autonomous charging paradigm in which an ensemble of identical two-level units, collectively coupled to a thermal environment, acquires work capacity without any external control. The common bath mediates interference between emission and absorption pathways, steering the many-body state away from passivity and into a steady regime with nonzero extractable work. The full charging dynamics and closed-form expressions are obtained for the steady-state, showing favorable scaling with the number of cells that approach the many-body optimum. We show that the mechanism is robust to local noise: under a convex mixture of collective and local dissipation, non-zero steady-state ergotropy persists, exhibits counterintuitive finite-temperature optima, and remains operative when the collective channel is comparable to or stronger than the local one. We show that environmental fluctuations can be harnessed to realize drive-free, scalable quantum batteries compatible with circuit- and cavity-QED platforms. Used as local work buffers, such batteries could potentially enable rapid ancilla reset, bias dissipative stabilizer pumps, and reduce syndrome-extraction overhead in fault-tolerant quantum computing.

Figures (15)

• Figure 1: Schematic representation of the charging process of the QB. On the left is the uncharged QB with each qubit constituting a cell of the QB. Depicted as cavity is the shared reservoir at a finite temperature $T_R$ that interacts with each cell collectively exciting each individual cell. As a result, the QB is charged as depicted in the right.
• Figure 2: Steady-state ergotropy under ideal collective dissipation. Heat map of the steady-state ergotropy $\mathcal{W}$ for $N=26$ with perfectly collective coupling ($\eta=1$) versus the common-reservoir parameter $\alpha_c$. Away from the fine-tuned line $\alpha_c=q$, $\mathcal{W}>0$ and typically grows as either $\alpha_c\to 1$ or $q\to 1$.
• Figure 3: Comparison of the ergotropic balance $\Delta \mathcal{W}$ after applying random unitaries. $\Delta \mathcal{W}$ is plotted against the ordinal index of the unitary, denoted by $\mathcal{I}_{U}$, for different system temperatures $\beta_{q}$ and two environment temperatures $\beta_{c}$. In all cases, the ergotropic balance satisfies $\Delta \mathcal{W} < 0$.
• Figure 4: Finite-temperature optima under partial collectivity. Steady-state ergotropy $\mathcal{W}$ for $N=7$, $\gamma_r=1$ with collective fraction $\eta=0.9$ as a function of $(\alpha_c,\alpha_\ell)$. Unlike the ideal case, the maximum occurs at a finite $\alpha_c^\star<1$ and a non-zero $\alpha_\ell^\star>0$, reflecting a trade-off between interference-enabled collective pumping (favored by larger $\alpha_c$) and which-path information injected by local channels (growing with $\alpha_\ell$) that degrades interference.
• Figure 5: Charging dynamics near the activation point. Ergotropy $\mathcal{W}(t)$ versus rescaled time $\gamma_c t$ for $N=10$, $\eta=0.9$ and various dissipation ratios $\gamma_r$. The collective bath is set close to its optimal value $\alpha_c^\star$; $\alpha_\ell=0$ is fixed across curves.

Theorems & Definitions (10)

• Theorem 1: Gershgorin's Circle Theorem
• Corollary 2.1
• Lemma 1
• proof
• Lemma 2: Lowering-induced leakage
• proof
• Lemma 3: Raising-induced leakage
• proof
• Proposition 1
• proof