Quantum walks as a tool to design robust quantum batteries: the role of topology and chirality

TL;DR

This paper explores how quantum walk-based topological and chiral properties of quantum batteries influence their energy storage capacity and robustness, providing insights for optimizing quantum energy devices.

Contribution

It introduces a novel approach using quantum walks to analyze the impact of topology and chirality on quantum battery performance, highlighting new mechanisms for optimization.

Findings

Chirality enhances ergotropy in complete quantum cells.

Topology influences ergotropy scaling and robustness.

Chirality can induce degeneracies to protect against decoherence.

Abstract

The maximum work that can be extracted from a quantum battery is bounded by the ergotropy of the system, which is determined by the spectral properties of the Hamiltonian. In this paper, we employ the formalism of quantum walks to investigate how the topology of the battery and the chirality of the Hamiltonian influence its performance as an energy storage unit. We analyze architectures of battery cells based on ring, complete, and wheel graph structures and analyze their behavior in the presence of noise. Our results show that these structures exhibit distinct ergotropy scaling, with the interplay between chirality and topology providing a tunable mechanism to optimize work extraction and enhance robustness against decoherence. In particular, chirality enhances ergotropy for complete quantum cells, without altering the linear scaling with size, whereas in ring cells, it bridges the performance gap between configurations with odd and even number of units. Additionaly, chirality may be exploited to force degeneracies in the Hamiltonian, a condition that can spare the ergotropy to vanish in the presence of pure dephasing. We conclude that topology and chirality are key resources for improving ergotropy, offering guidelines to optimize quantum energy devices and protocols.