Probing Electron Transport in PdCoO₂ with Single Spin Relaxometry

Spin relaxometry using nitrogen-vacancy (NV) centers in diamond offers a novel approach to probing local and nonlocal electronic transport in a variety of material systems. In this technique, the T₁ relaxation rate of a single, proximal NV center quantitatively probes the local magnetic field fluctuations generated by thermal electron motion. By varying its distance to the sample in a scanning probe geometry, the NV probes electron scattering at different length scales and can differentiate momentum-conserving and momentum-relaxing scattering. Here, we apply NV spin relaxometry to PdCoO₂, an exceptionally high mobility material at low temperature, and find evidence of strong temperature-independent momentum-conserving scattering below ~ 30 K. We also discuss the prospects and challenges of using spin relaxometry to probe hydrodynamic transport in materials with strong electron-electron interactions.

*This work is supported by Gordon and Betty Moore Foundation’s EPiQS Initiative via Grant GBMF10279 and UCSB Quantum Foundry through the NSF Q-AMASE-i program