Observation via spin Seebeck effect of macroscopic magnetic transport from emergent magnetic monopoles

Nan Tang; Stephan Glamsch; Aisha Aqeel; Ludwig Scheuchenpflug; Michael Schulze; Christoph Liebald; Daniel Rytz; Christo Guguschev; Manfred Albrecht; Philipp Gegenwart

arXiv · 2509.18422

Observation via spin Seebeck effect of macroscopic magnetic transport from emergent magnetic monopoles

Nan Tang·Stephan Glamsch·Aisha Aqeel·Ludwig Scheuchenpflug·Michael Schulze·Christoph Liebald·Daniel Rytz·Christo Guguschev·Manfred Albrecht·Philipp Gegenwart

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Abstract

Magnetic monopoles, elusive in high-energy physics, have been realised as emergent quasiparticles in solid-state systems, where their unique properties hold promise for novel spintronic applications. Magnetic monopoles have been invoked in diverse platforms, including skyrmion lattices, chiral magnets, soft ferromagnets, aritifical nanomagnets. Yet, a demonstration of their role in magnetic transport has remained elusive. Here, we report such an observation via the spin Seebeck effect in the bulk insulating pyrochlore oxide, spin ice $\mathrm{Dy_2Ti_2O_7}$. By applying a thermal gradient perpendicular to a $[111]$-oriented magnetic field, we detect a transverse spin Seebeck voltage marked by a dominant peak at the onset of monopole proliferation, accompanied by a secondary feature and frequency-dependent behavior. Our findings establish a direct link between monopole dynamics and magnetic transport in an insulating medium, establishing a new pathway for probing fractionalized excitations and advancing towards novel spintronic applications.

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Nan Tang, Stephan Glamsch, Aisha Aqeel, Ludwig Scheuchenpflug, Michael Schulze, Christoph Liebald, Daniel Rytz, Christo Guguschev, Manfred Albrecht, Philipp Gegenwart. 2025-09-22. Observation via spin Seebeck effect of macroscopic magnetic transport from emergent magnetic monopoles. https://arxiv.org/abs/2509.18422

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