Intrinsic one-dimensional conducting channels in the Kondo insulator SmB6

TL;DR

This paper uncovers evidence for robust one-dimensional conducting channels in the Kondo insulator SmB6, revealing a new conduction pathway that persists up to room temperature and may host exotic physics.

Contribution

It provides the first direct evidence of intrinsic one-dimensional conduction channels in SmB6, expanding understanding of its low-temperature transport mechanisms.

Findings

Detection of 1D conducting states at surface step edges

States remain conductive up to room temperature

Suggests a new conduction route in SmB6

Abstract

Since its discovery as a Kondo insulator 50 years ago, SmB6 recently received a revival of interest due to detection of unexpected quantum oscillations in the insulating state, discovery of disorder-immune bulk transport, and proposals of correlation-driven topological physics. While recent transport results attribute the anomalous low temperature conduction to two-dimensional surface states, important alternatives, such as conduction channel residing in one-dimensional dislocation lines, have not been adequately explored. Here we study SmB6 with scanning microwave impedance microscopy and uncover evidence for conducting one-dimensional states terminating at surface step edges. These states remain conducting up to room temperature, indicating unusual robustness against scattering and an unconventional origin. Our results bring to light a heretofore undetected conduction route in SmB6 that contributes to the low temperature transport. The unique scenario of intrinsic one-dimensional conducting channels in a highly insulating correlated bulk offers a one-dimensional platform that may host exotic physics.