Hysteretic Magnetotransport in SmB6 at Low Magnetic Fields

TL;DR

This study investigates the low-field hysteretic magnetotransport behavior of SmB6 surface states, revealing glassy magnetic ordering likely caused by surface oxidation, which is distinct from quantum interference effects.

Contribution

It provides new insights into the magnetic properties of SmB6 surface states, highlighting hysteretic behavior linked to surface magnetic ordering rather than quantum interference.

Findings

Hysteretic magnetoresistance depends on field sweep rate and temperature.

Slower field sweeps reduce hysteresis but do not eliminate it.

Surface magnetic ordering is likely due to samarium oxide formation.

Abstract

Utilizing Corbino disc structures, we have examined the magnetic field response of resistivity for the surface states of SmB6 on different crystalline surfaces at low temperatures. Our results reveal a hysteretic behavior whose magnitude depends on the magnetic field sweep rate and temperature. Although this feature becomes smaller when the field sweep is slower, a complete elimination or saturation is not observed in our slowest sweep-rate measurements, which is much slower than a typical magnetotransport trace. These observations cannot be explained by quantum interference corrections such as weak anti-localization. Instead, they are consistent with behaviors of glassy surface magnetic ordering, whose magnetic origin is most likely from samarium oxide (Sm2O3) forming on the surface during exposure to ambient conditions.