Curator's Take
This article demonstrates that a capacitively coupled double‑quantum‑dot battery can store most of its extractable work in non‑passive population distributions even when realistic 1/f charge noise is present, confirming recent theoretical predictions that ergotropy often hinges on population ordering rather than sustained coherence. By modeling the detuning fluctuations as band‑limited stochastic processes and showing how resonant tunnel‑coupling driving selects a dominant E0↔E3 transition, the work bridges the gap between idealized quantum‑battery proposals and semiconductor platforms where charge noise is unavoidable. The findings suggest that practical quantum‑battery designs can tolerate typical solid‑state dephasing while still delivering useful work, but also highlight that reducing low‑frequency detuning noise will be crucial for maximizing both population transfer efficiency and any transient coherence advantage.
— Mark Eatherly
Summary
We investigate extractable work storage in a capacitively coupled double quantum dot (DQD) quantum battery (QB) subjected to experimentally motivated detuning charge noise. The battery is modeled as two interacting charge qubits with an Ising-type capacitive coupling and is charged by resonant microwave modulation of the tunnel coupling channel. Detuning fluctuations are introduced as classical stochastic processes generated from a band-limited 1/f noise spectrum. For each noise realization, the evolution remains unitary, whereas decoherence and loss of contrast emerge after ensemble averaging. We analyze the total ergotropy, its population and coherent contributions, the energy basis populations, a passive ordering violation diagnostic, and the Jensen-Shannon coherence of the noise-averaged state. The results show that resonant tunnel coupling driving selects a dominant E0 <-> E3 population transfer channel in the interacting DQD spectrum. The dominant extractable work is stored in non-passive population distributions, in agreement with recent population ordering interpretations of ergotropy in QBs, while coherence accompanies and supports the resonant transfer as a transient dynamical resource. Detuning noise reduces the energy basis coherence amplitude and also weakens the population transfer pathway responsible for the dominant population ergotropy. This framework provides a noise-aware description of semiconductor QB charging based on extractable work rather than on injected energy alone.