Anomalous Hall effect in YIG$|$Pt bilayers

TL;DR

This study investigates the anomalous Hall effect in YIG|Pt bilayers, revealing temperature-dependent sign changes in spin mixing conductance and identifying a higher order Hall effect in thin Pt films at low temperatures.

Contribution

It provides new insights into the spin Hall anomalous Hall effect in YIG|Pt bilayers, highlighting the role of the imaginary part of the spin mixing conductance and discovering a higher order Hall effect.

Findings

Anomalous Hall-like signature in Pt depends on thickness and temperature.

Sign change in the imaginary part of spin mixing conductance between 10 K and 300 K.

Detection of a higher order Hall effect in thin Pt films at low temperatures.

Abstract

We measure the ordinary and the anomalous Hall effect in a set of yttrium iron garnet$|$platinum (YIG$|$Pt) bilayers via magnetization orientation dependent magnetoresistance experiments. Our data show that the presence of the ferrimagnetic insulator YIG leads to an anomalous Hall like signature in Pt, sensitive to both Pt thickness and temperature. Interpretation of the experimental findings in terms of the spin Hall anomalous Hall effect indicates that the imaginary part of the spin mixing interface conductance $G_{\mathrm{i}}$ plays a crucial role in YIG$|$Pt bilayers. In particular, our data suggest a sign change in $G_{\mathrm{i}}$ between $10\,\mathrm{K}$ and $300\,\mathrm{K}$. Additionally, we report a higher order Hall effect, which appears in thin Pt films on YIG at low temperatures.