Scanning Tunneling Microscopy and Spectroscopy on the Metallic Delafossite PdCoO₂

The metallic delafossite PdCoO₂ has risen to the limelight in the past few years [1]. Due to unusually long mean free paths, the electron fluid exhibits hydrodynamic effects [2].The anisotropic crystal structure leads to a quasi-2D character of the electronic states making the material suitable for surface sensitive techniques. Because of the polar nature of the surface, exciting physics is observed such giant Rashba spin-splitting [3] and itinerant ferromagnetism [4]. In our study, we have investigated the different surface terminations of PdCoO₂ with low temperature Scanning Tunneling Microscopy. We will discuss their assignment and spectroscopic signatures.