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arXiv · 2510.10391

Breakdown of the Wiedemann-Franz law in an interacting quantum Hall metamaterial

Patrice Roche·Carles Altimiras·François D. Parmentier·Olivier Maillet
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Abstract

Coulomb interactions deeply affect quantum transport in simple ballistic systems, but their impact on scaled up ballistic structures remains underexplored. Here we theoretically consider a chain of small metallic dots with frozen charge dynamics, connected by ballistic channels. We identify a neutral mode of transport, that is specific to a chain with at least two islands, and entwines local diffusion by neutral excitations with long-range correlations between islands' charge states. We show, as an experimentally measurable signature of this many-body behavior, that the Wiedemann-Franz law is violated with a Lorenz ratio scaling as the square root of the chain's length.

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Patrice Roche, Carles Altimiras, François D. Parmentier, Olivier Maillet. 2025-10-12. Breakdown of the Wiedemann-Franz law in an interacting quantum Hall metamaterial. https://doi.org/10.1103/twbt-z82z

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