Metallic Contact Contributions in Thermal Hall Conductivity Measurements

TL;DR

This paper examines how metallic contacts can influence thermal Hall measurements, revealing that they can produce signals similar to those observed experimentally, emphasizing the importance of minimizing contact effects for accurate results.

Contribution

The study demonstrates that metallic contacts can significantly affect thermal Hall measurements and provides guidelines to reduce their impact in experimental setups.

Findings

Metallic contacts can generate thermal Hall signals similar to sample responses.

Contact thicknesses around 1% of sample width can replicate experimental signals.

Optimizing measurement configurations reduces contact-induced artifacts.

Abstract

We investigate the influence of metallic contacts on thermal Hall measurements. By analyzing typical measurement setups, we show that heat currents bypassing through metallic contacts could generate non-negligible thermal Hall signals. We find that contributions from metallic contacts with thicknesses on the order of 10$^{-2}$ of sample widths can approximately replicate experimental observations across different materials in both temperature dependence and magnitude, assuming silver contacts with a conductivity of $10^{8}~\mathrm{S/m}$. Our analysis underscores the need to minimize metallic contact effects in thermal Hall measurements, which can be achieved by optimizing measurement configurations.