In-plane transport anisotropy study of oxygen doped iron telluride MBE thin films on LaAlO3 substrate

FeTe is well known for its simple crystal structure in the 11 family iron-based high temperature superconductors. We have observed two distinct in-plane transport phenomena in MBE grown FeTe thin films on LaAlO3 substrates. The first one is an unexpected global alignment of the in-plane transport anisotropy. A low temperature resistivity upturn feature has been observed in the neighborhood of the superconducting transition temperature as a function of transport direction. The resistivity upturn feature emerges from 8K to 20K. The second one is the coexistence of superconductivity with the low temperature resistivity upturn. We will report our studies of these distinct transport anisotropy experimental results comparing them with first principle simulations.