Year: 2026
Type: article
Abstract: We demonstrate how nonequilibrium magnons can drive the cooling by heating effect in a spin-selective quantum dot system. The mechanism relies on magnon-assisted spin-flip transitions that transfer electrons between two ferromagnetic electrodes maintained at different temperatures, with the magnetic insulator acting as the high-temperature energy source. In the limit of fully spin-polarized antiparallel electrodes, the transport enters a tight-coupling regime in which each absorbed magnon is accompanied by the transfer of a single electron. This one-to-one correspondence directly links the cooling power to the heat supplied by the magnonic reservoir and enables the thermodynamic performance to approach its upper bound. We further show how finite spin polarization introduces parasitic spin channels that suppress cooling and reduce the operating range. An extended dual quantum dot configuration restores cooling by heating without net charge current and enhances the cooling power. Our results establish magnons as a distinct microscopic energy carrier for cooling by heating and provide a route toward its realization in solid-state spin-caloritronic systems.
Source: New Journal of Physics
Authors: Emil Siuda, Piotr Trocha
Institution: Adam Mickiewicz University in Poznań
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,610
Funder: Narodowym Centrum Nauki
OpenAlex ID: W7223229947