Abstract
The two-dimensional layered compound PdCoO₂ is one of the best oxide conductors, providing an intriguing research arena opened by the long mean free path and the very high mobility of ~51000 cm2/Vs. These properties turn PdCoO₂ into a candidate material for nanoscale quantum devices. By exploring universal conductance fluctuations originating at nanoscale PdCoO₂ Hall-bar devices, we determined the phase coherence length of electron transport in c-axis oriented PdCoO₂ thin films to equal ~100 nm. The weak temperature dependence of the measured phase coherence length suggests that defect scattering at twin boundaries in the PdCoO₂ thin film governs phase breaking. These results suggest that phase coherent devices can be achieved by realizing the devices smaller than the size of twin domains, via refined microfabrication and suppression of twin boundaries.