Thermoelectric probe for Fermi surface topology in the three-dimensional Rashba semiconductor BiTeI

We have investigated thermoelectric properties of a three-dimensional Rashba system BiTeI. Magnetic-field dependences of the Seebeck effect and Nernst effect show qualitative changes with the Fermi level passing through the bulk Dirac point, indicating that thermoelectric effects can be a good experimental probe for the Fermi surface topology. The quantum oscillations are observed in the thermoelectric effect of BiTeI under a magnetic field, which are also dependent on the Fermi-level positions and consistent with the energy derivative of the three-dimensional density of states in the Rashba system.