When
Title: Manifestation of the Néel order-parameter fluctuations in the antiferromagnetic spin transport
Speaker: Hiroto Adachi, Research Institute for Interdisciplinary Science, Okayama University, Japan
Location: PAS 236 or zoom https://arizona.zoom.us/j/81745973847
Abstract: Spin transport has attracted much attention as a new probe of quantum materials [1], and the spin pumping/spin Seebeck eFect is established as a convenient means to examine spin transport properties. Here, we argue that an unconventional exchange coupling (Néel coupling) at a spin uncompensated interface gives rise to a spin transport that manifests the Néel order-parameter fluctuations. First, we demonstrate that the Néel coupling brings about a divergent and strongly frequency-dependent enhancement of the spin pumping signal in a ferromagnet/antiferromagnet/heavy metal trilayer [2,3]. Second, we show that the Néel coupling can explain the convex downward temperature dependence of the spin Seebeck eFect near Tc observed in a ferrimagnet/heavy metal bilayer [4,5].
[1] W. Han et al., Nat. Mater. 19, 139 (2020).
[2] See Fig. 4 in Z. Qiu et al., Nat. Commun. 7, 12670 (2016).
[3] Y. Furutani, HA et al., Phys. Rev. B 112, 174416 (2025).
[4] K. Uchida et al., Phys. Rev. X 4, 041023 (2014).
[5] H. Fukushima, HA et al., Phys. Rev. B 112, 134415 (2025) [selected as a PRB Editors’
Suggestion].