Spin Seebeck Effect in Correlated Antiferromagnetic V2O3

TL;DR

This study demonstrates a significant longitudinal spin Seebeck effect in antiferromagnetic V2O3 thin films, revealing insights into spin correlations, magnetic order, and magnon dynamics at cryogenic temperatures.

Contribution

It reports the first observation of a strong LSSE in V2O3, highlighting the role of bulk magnon contributions and spin-lattice coupling in antiferromagnetic insulators.

Findings

LSSE increases with magnetic field and peaks at certain temperatures.

The LSSE magnitude decreases with increasing film thickness.

Magnon energy relaxation length is shorter than 50 nm, indicating strong spin-lattice coupling.

Abstract

The spin Seebeck effect is useful for probing the spin correlations and magnetic order in magnetic insulators. Here, we report a strong longitudinal spin Seebeck effect (LSSE) in antiferromagnetic V2O3 thin films. The LSSE response at cryogenic temperatures increases as a function of the external magnetic field until it approaches saturation. The response at given power and field exhibits a non-monotonic temperature dependence, with a pronounced peak that shifts toward higher temperatures as the field increases. Furthermore, the magnitude of the LSSE signal decreases consistently with increasing thickness, implying that the bulk SSE dominates any interfacial contribution. This negative correlation between the SSE and the thickness implies that the magnon energy relaxation length in V2O3 is shorter than the thickness of our thinnest film, 50 nm, consistent with the strong spin-lattice coupling in this material.