Abstract
We use scanning tunneling microscopy/spectroscopy to elucidate the Cooper pairing of the iron pnictide superconductor . By a cold-cleaving technique, we obtain atomically resolved termination surfaces with different layer identities. Remarkably, we observe that the low-energy tunneling spectrum related to superconductivity has an unprecedented dependence on the layer identity. By cross referencing with the angle-revolved photoemission results and the tunneling data of LiFeAs, we find that tunneling on each termination surface probes superconductivity through selecting distinct orbitals. These findings imply the real-space orbital features of the Cooper pairing in the iron pnictide superconductors, and propose a general concept that, for complex multiorbital material, tunneling on different terminating layers can feature orbital selectivity.
- Received 20 March 2020
- Revised 20 July 2020
- Accepted 5 August 2020
- Corrected 20 October 2020
DOI:https://doi.org/10.1103/PhysRevB.102.054515
©2020 American Physical Society
Physics Subject Headings (PhySH)
Corrections
20 October 2020
Correction: A conversion error resulted in wrong affiliation indicators to be set for the last author S. H. Pan in the PDF format and has been fixed. The HTML version was processed correctly, without incident.