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arXiv · 2503.13141

Gate electrode-induced nonreciprocal resistance in topological insulators

Sofie Kölling·Florian R. Westerhof·Alexander Brinkman
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Abstract

A common method of controlling the chemical potential in topological insulators is applying a gate electrode. Simultaneously applying high source-drain bias currents can lead to parasitic effects in such devices. We derive that these parasitic effects lead to a gradient in the Hall effect along the current lead of a Hall bar. Consequently, nonreciprocal effects in both longitudinal and Hall voltages appear upon reversing the bias. These effects scale similarly to the magnetochiral anisotropy, requiring detailed analysis to make a distinction. Experimentally we show that nonreciprocal effects can appear in materials where magnetochiral anisotropy is not expected while a top gate is present. Without gate electrode, this nonreciprocal effect is found to be absent. These results show the importance of considering and, if possible, excluding gate electrode-induced effects when searching for nonreciprocal resistance intrinsic to a material.

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Sofie Kölling, Florian R. Westerhof, Alexander Brinkman. 2025-03-17. Gate electrode-induced nonreciprocal resistance in topological insulators. https://arxiv.org/abs/2503.13141

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