# Surface-induced positive planar Hall effect in topological Kondo insulator SmB6 microribbons

## TL;DR

This study demonstrates a positive planar Hall effect in SmB6 microribbons, attributed to topological surface states, with the effect's magnitude varying with temperature, supporting the topological nature of these surface states.

## Contribution

It provides experimental evidence of surface-induced positive PHE in SmB6, indicating the topological character of its surface states through magneto-transport measurements.

## Key findings

- Positive PHE increases as temperature decreases below 5 K.
- Negative PHE observed in bulk states at high temperatures.
- Surface states exhibit a much stronger PHE than bulk states.

## Abstract

Whether the surface states in SmB6 are topological is still a critical issue in the field of topological Kondo insulators. In the magneto-transport study of single crystalline SmB6 microribbons, we have revealed a positive planar Hall effect (PHE), the amplitude of which increases dramatically with decreasing temperatures but saturates below 5 K. This positive PHE is ascribed to the surface states of SmB6 and expected to arise from the anisotropy in lifting the topological protection from back-scattering by the in-plane magnetic field, thus suggesting the topological nature of surface states in SmB6. On the contrary, a negative PHE is observed for the bulk states at high temperatures, which is almost three orders of magnitudes weaker than the surface-induced positive PHE.

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Source: https://tomesphere.com/paper/1902.07364