Extracting linear and nonlinear conductivity tensors using angle resolved transport

Measuring electrical transport with angular resolution is a powerful experimental tool to extract information about linear and nonlinear conductivity tensor of the material. The extraction procedure is complicated by the geometric effects, which alter the readout of the potential drop on contacts. We present a theory of linear and nonlinear transport with angular resolution in sunflower geometry up to quadratic order in injected current. We provide analytical solutions for the linear and nonlinear components of electrostatic potential, which accommodate the effects of sample geometry. This allows us to extract all components of linear and nonlinear conductivity tensor and analyze whether the currents in the sample are dissipative (Ohmic) or non-dissipative (Hall-like).