SPICE Workshop on Non-equilibrium Quantum Materials Design, June 27th - 29th 2023
Carsten Putzke
In the pursuit to develop new and more powerful electronics, semiconductor research has pushed the sample size over many decades to the nanometer scaler now aiming for single electron transistors. By achieving this, new length scales have become more important leading to hydrodynamic, ballistic and quantum transport phenomena. To realize these regimes in strongly correlated electron systems requires samples in the order of a few micrometers even in high quality single crystals. To achieve this, we use focused ion beam (FIB) machining. This gives us control of sample shape, size and current path orientation with nanometer precision.
In the first part of my talk I will show you how finite size confinement allows us to achieve precise current flow in highly anisotropic crystals. With this we can demonstrate the particle-like (ballistic, in-plane) and wave-like (phase coherent, out-of-plane) nature of the electronic transport in the anisotropic, single band metal PdCoO2 [1,2]. By using angle dependent magnetic field measurements of the out-of-plane transport we can further demonstrate the crossover from finite size to bulk transport regime (see figure below). I will give an outlook how this finding can open a new route to study the elusive Pseudogap in high purity cuprate superconductors [3].
1: Bachmann, et al. Nat. Comm. 10, 5081 (2019).
2: Putzke, et al. Science 368, 1234 (2020).
3: Putzke, et al. Nature Physics (2021).