Scanning Tunneling Microscopy studies on CeCoIn$_5$ and CeIrIn$_5$

TL;DR

This study uses low-temperature scanning tunneling microscopy to analyze the surface and electronic properties of heavy fermion superconductors CeCoIn$_5$ and CeIrIn$_5$, revealing a persistent gap above the critical temperature and surface atom rearrangements.

Contribution

Established methods for in-situ cleaving and performed detailed STM analysis on CeCoIn$_5$ and CeIrIn$_5$, providing new insights into their surface structure and electronic states.

Findings

Detection of a superconducting gap persisting above T_c in CeCoIn$_5$

Observation of atom rearrangement at the crystal surface

Surface modifications potentially affect tunneling spectroscopy results

Abstract

High--quality single crystals of the heavy fermion superconductors CeCoIn$_5$ and CeIrIn$_5$ have been studied by means of low--temperature Scanning Tunneling Microscopy. Methods were established to facilitate \textit{in-situ} sample cleaving. Spectroscopy in CeCoIn$_5$ reveals a gap which persists to above $T_c$, possibly evidencing a precursor state to SC. Atomically resolved topographs show a rearrangement of the atoms at the crystal surface. This modification at the surface might influence the surface properties as detected by tunneling spectroscopy.