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.
- Pub Date:
- May 2021
- Condensed Matter - Strongly Correlated Electrons;
- Condensed Matter - Mesoscale and Nanoscale Physics;
- Condensed Matter - Materials Science
- Upon further follow-up studies, we discovered additional data in different parameter spaces that weakened our arguments. While this does not preclude the existence of 1-D conducting states, we feel that our previous supporting arguments are rendered ineffective, and we must suspend and withdraw our manuscript at this point