Extracting linear and nonlinear conductivity tensors using angle resolved transport

The ability to examine the spatial anisotropy is central to our understanding of an electronic system. By probing transport properties with angular resolution, angle resolved transport measurement (ARTM) offers a powerful method to extract information of the spatial symmetry. Enabled by the new "sunflower" geometries, we use ARTM to determine both linear and nonlinear conductivity tensors from multiple samples. These conductivity tensors, which are generally inaccessible to the traditional Hall bar geometries, together offer an accurate description of the diffusive transport behavior across the samples up to second order in current. We show that the theoretical model is in excellent agreement with data, unlocking a new path towards a full characterization of the electronic anisotropy across the phase space of different graphene allotropes.